The scene opens in early colonial America, in Massachussets. A combination gallows/pyre has been constructed for an execution by both hanging and burning, and a man is shown roughly loading feral cats into a wicker basket. Village elders are entering a small tower being used as a prison; its door engraved with a hex mark. At the top of the tower, a man (Julian Sands) is chained, including a peculiar shackle that locks his thumbs to his big toes. The man is to be executed for 'trafficking with the Devil,' and is being offered a final chance to confess his sins before man and God. However, the warlock is completely unrepentant and does not speak to the jailer or elders. The elders leave to continue preparing for the execution.
Entering the cell next is a stoic man named Redferne (Richard E. Grant), a witch hunter who helped capture the warlock. He gloats over the warlock's meeting a well-deserved fate, asking whether Satan would have saved the warlock yet, if he wanted to at all. The warlock slyly suggests that Satan may yet save them both. Redferns kicks him in the face, knocking him onto his back and says he'll watch the warlock die tomorrow. The warlock tells him to believe it on seeing it... tomorrow.
As Redferns leaves, he warns the jailer that the thumb locks must not be removed from the warlock even during or after the execution; not until his corpse has completely finished burning to ash. But even as he speaks, there are sounds of a storm brewing. As Redferne exits the tower, a powerful, clearly unnatural storm breaks over the village, and Redferne notes it is centered over the warlock's prison tower. Redferne rushes into the cell to find the warlock free of his shackles and channeling a powerful spell. Redferne rushes at the warlock, trying to stop him, but the spell completes, and both Redferne and the warlock vanish.
Cut to modern day Los Angeles. We hear a radio broadcast about a storm breaking; one nicknamed, 'The Devil's Wind.' A funnel of air is seen heading toward a suburban house. A blonde woman, Kassandra (Lori Singer) is turning over in her bed, asleep until the sound of a breaking window jolts her awake. She goes to investigate, quickly joined by Chas (Kevin O'Brien), the owner of the house, from whom she rents her room. They find the warlock lying unconscious on the floor of the living room.
Chas goes to call the police to get an ambulance, but the winds have knocked down phone lines throughout the area. He and Kassandra half-pull, half-carry him to Kassandra's room. Kassandra is wary but Chas wants to show the strange arrival some compassion.
Morning arrives and Kassandra is dressing and preparing for work. We see that she is diabetic and must take regular injections of insulin (very important plot point later).
Going back to her room, she sees the warlock is awake and slyly suggests he stop drinking. As she asks if there's someone he can call, as the phones are working again, the warlock is staring in amazement at a weekly newspaper on her desk, dated March 4-10, 1988. He asks if that could truly be the year, though it appears he is talking to himself as much as Kassandra. She is amused at his voice inflections, noting he speaks, '*English* English.' She gently presses him back down on the bed and tells him to rest. On the road, driving to work, Kassandra is shown to be both a bit careless in her driving, not always watching the road, and a bit vain, praying she never gets old.
Back at the house, Chas is cooking a meal. Picking up a knife he's dropped, he's briefly started on seeing the warlock's reflection. The warlock just smiles politely and stands silently in the kitchen while Chas talks to him. He notices the warlock looking at a ring on his pinky finger, and says it's his birth sign (Scorpio) but nobody believes in astrology anymore, which surprises the warlock. Suddenly when Chas is off guard the warlock grabs a knife and hacks Chas's pinky off, taking the ring. Chas screams for help, but the warlock gestures and the kitchen door closes, trapping Chas in the kitchen. Donning the ring, the warlock grabs Chas and bites his tongue out, spitting it into the skillet.
Kassandra is seen at work, as a short order cook/waitress at a small coffee shop. A police cruiser arrives in front. We then see a police detective asking Kassandra questions about Chas, telling her the coroner's notes on the cause of his death. He asks Kassandra for the names of Chas's lovers (Kassandra had told him that Chas was gay), and says he wants to catch the man who killed him.
Over at a bookstore selling books on the metaphysical, a group is leaving after conversation with a spirit, happy at the results of the spirit channeling. The Channeler (Mary Woronov) starts to close up when she sees the warlock in the shop. He asks her to channel a spirit for him. She is allured at his charismatic nature and agrees to his request.
The Channeler begins the private channeling for the spirit that the warlock said had many names, one of which was Zamiel. As the Channeler completes the summoning, the warlock immediately sees through the ritual and notes that she is a fraud. But he only says that he wishes to wait for the true Zamiel to appear. Trying to keep up the charade, the Channeler says the warlock must cast aside his skepticism. But suddenly she begins to gasp and choke. Her hands almost involuntarily close around a crystal, and it shatters. Her head falls forward onto the table, and then snaps back up, and her face has become demonic; her teeth huge and like shark's teeth. The warlock asks why he was brought to this place and time. Zamiel, speaking through the Channeler, tells the warlock to bring together his 'bible,' which has been divided into three parts. The warlock is amazed to hear that this book, which he calls the Grand Grimoire, is here, now. Very interested, he asks what reward was in store for him if he succeeded in retaking the book-- which he understands, can 'thwart Creation itself.' Zamiel tells the warlock that if he succeeds, he shall become Satan's one begotten son. His eyes will guide the warlock. The Channeler then collapses face-first back onto the table. The warlock picks up a shard from the crystal and lifts the Channeler's head back up. She is dead and her face has reverted to normal. The warlock uses the sharp edge of the broken crystal shard to remove her eyes, and they are shown to be moving-- a guide for the warlock.
Kassandra arrives home, not quite comfortable in the house now that Chas has been murdered. She closes a door, and a shadow appears from a sliver of light behind it as she walks away. Going to her room, Kassandra starts to gather her things, deciding to leave the house. The sound of shattering glass attracts her attention.
Going to investigate, she sees a cat run across the hall. Relieved, she resumes packing, but then sees Redferne in the doorway. She screams in fear, and he rushes to cover her mouth, holding up the thumb-lock device, demanding to know if "the one who wore these bled at all, anywhere." She screams again and he slaps her face. She tries to punch him, but he grabs her and drags her to the kitchen where a police chalk outline still shows where Chas was found. Redferne tells Kassandra that he can find 'the beast' if he knows if his blood was spilt. Kassandra finally realizes that Redferne is talking about the warlock and finally admits that he had been cut. Redferne asks her to show him where. Kassandra goes to the vacuum cleaner and empties out the dust bag. Sifting through the dust, Redferne finds a shard of broken glass with blood on it. He fiddles with it, using his dagger, saying it may do. He scrapes the dried blood from the shard into a small glass vial.
While he works, Kassandra sneaks into the next room and calls the police. She tells them there is an intruder, and she doesn't know what to make of him, but he "has a thing for blood-- draw your own conclusions." The operator traces her call and gets her address and tells her a car is on the way. Kassandra says she's fleeing the house, though she doesn't get far after hanging up before Redferne grabs her, now wanting to know where her water well is. Amused despite her fear, at the man asking for a water well, she takes him to the bathroom and shows him how to use the sink. He puts a little bit of water into the vial with the blood. She watches, perplexed, as he sets up a strange device. At her query, he explains it is a witch compass and she understands that he is hunting the blond man who had been in the house, and Redferne says that this man was a warlock. He puts a drop of the blood onto the compass, saying that the compass will point in the warlock's direction. Kassandra watches, now interested, but mocks Redferne when the device doesn't appear to work. Redferne tells her to give it time, as the blood was thin, but Kassandra hears the arrival of the police squad car and tells him that he doesn't have any time. Redferne rushes to the door and is taken aback at the automobiles, something he's seeing for the first time and has no idea what they are. He goes outside, not understanding who the officers are. The police order him to freeze. Thinking he is being attacked, Redferne uses his whip to try and defend himself, but an officer subdues him with a taser gun.
Redferne spouts about the warlock's evil as he is loaded into the squad car. The lead officer tells Kassandra they'll take him down to the station, and advises her to leave the house. Kassandra is very agreeable to this and rushes to resume packing her things.
Hurrying between the house and her car, stuffing as much as will fit into the car, Kassandra grabs some things from the bathroom. But the needle of Redferne's witch compass, still resting on the bathroom counter top, suddenly begins to move, and she notices. Approaching the door, Kassandra freezes in fear on spotting the warlock just outside, holding a pair of disembodied eyes in one hand-- eyes that seem to move on their own. She rushes to close and lock the door, and rushes back to her phone to call the police again. This time however she only reaches the automated hold system. She sees the witch compass needle begin to spin and drops the phone in fear. She rushes to secure all the doors and windows of the house, but she is too late as the warlock is behind her.
The warlock drags her by her hair into the living room, watching the disembodied eyes in his other hand. They lead him to an antique coffee table, and he sweeps everything off of it. Kassandra runs to the bathroom and locks herself inside as the warlock smashes the table apart, finding a sheaf of papers inside which are covered in strange writing and drawings. Inside the bathroom, Kassandra tries to open the shutters and escape through the window. Suddenly the warlock's hand smashes through and grabs her wrist. Screaming in terror, Kassandra yanks her wrist free and loses her balance, falling to the floor and hitting her head, knocking herself out. The warlock had managed to grab the charm bracelet off of her wrist. Holding it, he sticks his head through the window and recites a dire chant before leaving.
Morning comes before Kassandra comes to. Struggling to regain her bearings, she realizes that her hair has grown far far longer than she keeps it cut. Rushing to look at herself in the mirror, she finds to her horror that she looks about twenty years older.
Kassandra is leaving the police station with Redferne, having bailed him out of jail. She realizes that the warlock put a hex on her to age her from twenty years old to forty, and she needs Redferne's help as he seems to know a great deal about the warlock. Driving down the street, Redferne is completely dumbfounded at the world around him. He's finished explaining to Kassandra that the year was 1691 last he remembered. Both of them are still in shock that he and the warlock have come from 300 years in the past, to the present-- and neither of them has any idea why.
Back at the house, Redferne is examining the broken table. Kassandra stops him and asks how they fix her age. He asks if the warlock took a small, personal object from her, and she remembers that he took her charm bracelet. Redferne says the only way to break the hex is to regain the bracelet from the warlock. Kassandra is too frightened to pursue the warlock and tells him he must go on his own. Redferne warns her that the spell placed on her is not complete, but progressive. Each day she will age another 20 years-- meaning within two days, three at most, she will die of old age.
Kassandra and Redferne are preparing to pursue the warlock, though Kassandra makes it clear that she's only looking to reclaim her bracelet-- whatever quarrel Redferne has with the warlock, as far as she is concerned, is between them and none of her business. Redferne nods curtly and they start off.
As the warlock walks across the mesa, studying the papers he took from the broken table, Redferne is busying himself coating his whip with salt taken from the house. He explains to Kassandra that salt is taboo to witches. Again we see Kassandra's careless driving style as Redferne must grab the wheel to steer the car away from the wrong side of the road-- and away from an onrushing truck.
A young boy is playing with a football in a small trailer park. He throws it and is surprised to see a man catch the football-- the warlock. The boy takes the warlock to the nearby playground, and shows him how to play a hand-held football video game. The warlock is distracted by the sound of singing and music. The boy explains that it's coming from the church a few dozen yards behind them. He doesn't attend church because his father is not a believer. He asks the warlock why he doesn't attend, and the warlock says that witches cannot set foot on church grounds. He finds to his delight that the people of this time-- like the boy-- don't believe in witches, and that in legend, witches are all women. The boy asks where the warlock's flying broomstick is, if he's really a witch. The warlock says he needs no broomstick to fly. When asked what he does need, the warlock just laughs and gently pushes the swing that the boy is sitting on.
Kassandra pulls into a roadside gas station to refill her gas tank. Redferne sets up the witch compass while the car is being refilled and notes the needle moving in the direction of the park. Gunshots are heard, and the station attendant explains that local residents are hunting coyote, because a small boy in the nearby trailer park was killed by one. The attendant says that coyotes are known to do that in this part of the state, and the boy was badly chewed up, his skin taken clean off. Redferne's face turns very grim as he hears more gunshots.
Redferne and Kassandra head to the trailer park where they see the hunters dropping the corpse of a coyote they'd killed on the ground. A small crowd is gathered, murmuring. Redferne notices one woman's reaction, and her face as she walks away. He rushes after her, asking if she is the boy's mother. When she acknowledges that she is, he offers her his sympathy, but then gently presses to know if the boy had been baptized. Although irritated at such a question from a stranger, she finally admits that the boy's father wouldn't allow it.
Kassandra notes that Redferne suspects the warlock as the boy's murderer. Redferne explains to her that of all the various spell reagents used by witches, the most precious is human fat-- and if that fat is cut from a male child that has not been baptized, there is one thing it would be used for-- a flying potion.
At night, Redferne's grim words prove true, as the warlock cooks the fat in a small metal can over a flame that burns blue. He drinks the foul brew, and a police officer on speeding stakeout is dumbfounded at the sight of a strange man flying through the air at incredible speed.
Kassandra is trying to make small talk with Redferne to pass the time as they travel down the road. She is startled by his sudden question on why she paints her face. She tries to explain that in modern times, makeup is considered perfectly acceptable. Redferne blurts out that if "My Marion had--" and suddenly stops, saying only that in the 17th century, women didn't wear make-up unless they practiced witchcraft. Kassandra realizes that Redferne had accidentally let slip something he didn't want to talk about-- he was married. She tries to press for more information when Redferne insists they stop the car so he can get new bearings via the compass. Kassandra chastises herself as Redferne sets the compass up on the road... and then realizes she is feeling very ill. Redferne notices her stumbling out of the car, and she begs him to leave her by the road and go on without her. Her voice has changed drastically. Midnight has passed, and Kassandra has aged to sixty years old. Redferne can only comfort her.
Morning comes, and the warlock has secreted himself in the attic of a farmhouse. He is studying the papers, and is pleased at his new-found ability to create and control witch-fire. Even hidden, however, the warlock's very presence alters the environment around him-- the farmer's father goes to tell him that the cream has gone bad, which puzzles the farmer as he only brought it in yesterday. He asks his father to bring out one of the horses, and the father finds the horse deeply agitated, and wet. Walking toward the house, he notices the attic's door onto the roof is ajar. Watching his young grandchildren run by, racing each other, the elderly man takes paint and a paintbrush, and begins painting something on the barn.
Kassandra and Redferne are passing the state border into Colorado. Kassandra finally gets Redferne to tell her about Marion. She realizes that this is why he is pursuing the warlock-- he killed Redferne's wife.
They are passing by the farm and Redferne is shocked to see a hex mark painted on the side of the barn, and the witch compass needle moves to point toward it. Redferne urges Kassandra to stop and begins running toward the farm. The witch compass is broken by the hard stop, but Redferne says that if God is with them, they won't need it any longer.
They rush into the house and confront the farmer, Redferne saying that they are bewitched. The farmer is startled and wary at the intrusion until his father comes into the room, saying he painted the mark, and they are bewitched. The farmer's father is a Mennonite. He and Redferne shake hands in a comradely fashion, and he takes Redferne to show him the ajar attic door. Redferne has the Mennonite retrieve nails and a hammer, which he uses to nail the door shut. Back in the house, the farmer and his wife are still amazed at how his father is giving Redferne almost free run on the property. Redferne says that if children are present, to take them away. The Mennonite agrees and urges his son and daughter-in-law to take the kids and go. A horse that sweats in the morning, cream that sours overnight-- even his son, a modern-day farmer, has learned the signs that the Mennonite recognizes and believes in.
The farmer and his wife take the kids and drive off. Redferne is preparing to enter the attic from the retractable staircase connecting it to the farmhouse's hallway. He gives Kassandra and the Mennonite copper pennies to hold between their lips, as a ward against errant magic. On his word they are to close the steps and brace the door shut, and not re-open it until he says it is okay.
Pulling his whip and bodkin knife, Redferne enters the attic. He's startled by a flying bat and quickly slays it. Noting a small window braced open, he knows the warlock was-- or still is-- there. Looking around, he finds a broken piece of furniture, and a piece of paper inside, covered with drawings and writing. He quietly reads a few words from the paper, then tears it in half and puts the pieces on the floor. As the two pieces begin to move toward each other and reform into a single untorn sheet, Redferne realizes with horror that it is a page from the Grand Grimoire. He rushes to the stairs to tell Kassandra and the Mennonite about it-- the Grand Grimoire, an indestructible book of black magic said to be authored by Satan himself-- his bible. The Grimoire was last held by the West End church in Boston. Redferne had urged them to divide the book into three parts to prevent witches from seizing it and gaining access to all of its secrets, but the pages were supposed to be kept on hallowed ground. Kassandra interrupts him, asking where the warlock is. Redferne says, exasperated, that he's fled. But Kassandra points out that if the Grimoire was so precious to witches, why would he leave even a single page behind? Realizing Kassandra's point, he shouts for them to close the steps.
Redferne rushes back into the center of the attic, ready for battle, when the warlock lands to confront him. Redferne shouts for the Mennonite to fix the brace, which the warlock scoffs at, pointing out he can now fly. Redferne promptly uncoils his whip, yanking out the small brace in the window to close it. He then advances on the warlock and jams his bodkin deep into the warlock's middle. But he finds to his dismay that the warlock had placed the Grimoire pages under his shirt, and they acted as armor; the deep tear in the pages mending instantaneously. The warlock marvels at how even just two-thirds of the Grimoire could do this. He then counterattacks with a bolt of witchfire, causing Redferne to bust through the nailed attic door and tumble out onto the ground. Retrieving the page left behind, the warlock steps out onto the roof and with his magic, causes the weathervane to break loose from the roof and hurtle at Redferne like a spear. It narrowly misses, and Redferne coils his whip around the warlock's ankle as he starts to fly off. The warlock drags him across the farm and flies into the barn, where Redferne collides with the barn wall and loses his grip. Kassandra and the Mennonite regroup with him, having retrieved the weather vane, which Redferne holds ready. When the warlock re-emerges, Redferne hurls it like a javelin, nailing the warlock in the back and forcing him to land. The three pounce on him, pull his boots off and hold him down, where Redferne scrambles to affix the thumb-toe locks. Kassandra scrambles to recover her bracelet, but finds only the Channeler's eyes, which she tosses away in disgust. The warlock finds his avenue of escape-- he stares into the Mennonite's eyes. Redferne notices, but too late-- the warlock has placed a vile hex that is causing the Mennonite's eyes to bleed. Feeling the warlock has slain too many, he lets go of him to tend to the stricken Mennonite. The warlock is able to hobble and hop away, the locks not completely in place.
Redferne calls for brass keys to remove the hex. He also gives Kassandra the hammer and remaining nails, saying that if she finds footprints from the warlock, to hammer the nails into the ground there. Kassandra is furiously angry at the thought of facing the warlock with a simple nail, but Redferne insists she go and do as he says-- the warlock can be crippled that way.
Kassandra heads off, finding her way to a railway station near the farmhouse. She discovers foot prints made from a bare foot and hammers the nails into the dirt. She hears the warlock scream in agony, and we see him holding his feet as he hides in a railway car. Kassandra drives a nail into another foot print, but this time there is no scream-- the warlock had ripped a plank up from the railway car and is holding it against his feet like a shield. But then Kassandra finds an indentation made in a small pile of dirt, by the warlock's head when he stumbled and fell while removing the thumb-lock device. She drives a nail in and the warlock falls unconscious. His arm dangles limply out of the car and Kassandra sees her charm bracelet around the warlock's wrist. But the railway car begins moving, and Kassandra's supernaturally-aged, sixty-year-old body struggles desperately to catch up. She finally manages to grab the warlock's wrist, but the warlock comes to and grabs her wrist in return. She hits his hand with the hammer, causing him to lose his grip and her to fall to the ground. She watches in dismay as the train carries the warlock off... but then notes that the hammer pulled her charm braclet off the warlock's wrist, and both hammer and bracelet lie on the ground just a few feet in front of her.
Redferne has finished treating the Mennonite's eyes and covered them with a dressing. He has placed the brass keys above his head, to be spun clockwise once per hour. By morning the hex would be gone and his eyes recovered. He hears Kassandra ask about the Mennonite. Only her silhouette is visible from the darkened entrance to the bedroom. Redferne offers no excuse other than his wish to save just one life that the warlock would have otherwise taken. Saying she understands, Kassandra steps into the light, showing that the hex on her is likewise broken and her body has been restored to its original youth at twenty years of age.
They are heading back to Kassandra's car, Redferne saying that it is easy enough to gather brass, copper and glass to rebuild the compass. The most important thing is the weather vane, which has a new supply of the warlock's blood. But Kassandra wants no further part of the witch hunt now that she is restored to normal. She hands Redferne her car keys and credit card, wishing him well. He grabs her and she protests that the deal was only until she got her bracelet back. Having never learned Kassandra's name, he asks her for it, and proceeds to tell her that her life is still in grievous danger-- in fact all life is, now that he knows what the warlock is up to. The warlock has recovered two portions of the Grand Grimoire. If he gains the third part and completes the book, he will gain access to its ultimate secret-- the lost, true name of God. This true name was invoked during Creation... and witches claim that if the true name of God were to be pronounced in reverse, and spoken backward, all of Creation would also reverse-- the whole of the universe would "Uncreate" and cease to exist. Kassandra groans in dismay. She is terrifed of the warlock, and it shows plainly. On the next confrontation, there would be no spells or hexes-- she is sure that next time, the warlock would kill her. Redferne promises to protect her as he holds out the car keys.
Driving down the road again, Kassandra has come up with a plan. The Grimoire was last kept by the West End Church in Boston. Instead of playing tag, as she explains to Redferne, they should play 'leap frog' instead-- hurry to get to Boston before the warlock and make sure the last pages are safe on hallowed ground. They drive to the airport and Kassandra calls Operator Assistance to get the West End Church's address. Kassandra gives the ticket agent her credit card, but when the agent is distracted by another customer asking a quick question, Kassandra stealthily unplugs the card reader.
Noticing that the "plane" Kassandra speaks of is able to fly through the air like a bird, Redferne is very nervous and uncertain. In his time, humans even trying to fly were believed to practice witchcraft. Kassandra suddenly notices Redferne still has the weather vane attached to his back. She tries to grab it away, arguing he wouldn't be allowed on the plane with it. But suddenly she sees the warlock in the airport-- the warlock was no fool, and had figured out how to beat them at their own game. She shoves the vane back into Redferne's hands and drags him off to the plane. On board, during the evening, Kassandra tries to get Redferne to settle down and sleep. But he notices another passenger putting cream in his coffee and noticing it is spoiled, and another passenger lighting a cigarette with a cigarette lighter, and the flame is pure blue. Redferne knows these are signs of a witch's presence. Kassandra tries to calm him, and he realizes that she saw the warlock in the airport and didn't tell him. He insists they look for the warlock on the plane. But the warlock has secreted himself in the baggage hold in the plane's underside, out of sight.
The plane lands in Boston. Airport agents open the baggage hold door and are startled at what looks like a man flying out. Cut to Kassandra and Redferne in a taxicab, hoping to find the church. Boston has changed considerably in the last 300 years and Redferne isn't sure the church's location is still the same, or if it even exists anymore. Recalling his knowledge of certain landmarks as best he can, Redferne manages to aid the cab driver in finding the correct church. They arrive just as the Pastor of the Church is closing up. The Pastor is looking to get home, but when Redferne says he needs to speak about the Grand Grimoire, he re-opens the doors and brings them inside.
The Pastor says that Church documents aren't for sale, thinking that they are collectors of old documents. Kassandra says that they just need to find the book. The Pastor says it is long gone, divided up and-- he is interrupted by wind blowing the doors open, which alerts Redferne that thw warlock is around. Closing the doors again, the Pastor inquires into their interest in the Grimoire, and is shocked at Redferne's explanation.
He retrieves and opens an old folder of Church papers going back to 1692 and detailing the separation of the Grand Grimoire. One part was placed within the hollow of a table used in taking communion. The second part was given to a vicar who had founded a ministry west of the Carolinas, placed within an armoire. Over the years and centuries as witchcraft was forgotten and people no longer believed in it, these objects ended up sold and donated, re-sold and re-donated, until the table ended up at Chas's house, and the armoire in the Mennonite's attic. As for the third part... the Pastor says it should still be in Boston.
Kassandra and Redferne are walking down the road. The last part of the book is in an old graveyard that Redferne remembers existing even back in his day. The layout of the town is very different, but some subtle similarities remain. He manages to locate the graveyard, saying that if the ground there is consecrated, then the pages are safe, for the warlock can never set foot there.
Meanwhile, the Pastor is back home. His wife alerts him to a sound she's heard. They both note that the door is rattling and shaking-- in fact the whole house is shaking. The crucifix falls off the wall. Finally the bolts in the door's hinges slip out. The rumbling stops and the warlock pushes the door open from the hinged side. He forces the Pastor and his wife into chairs. With only a touch to the wife's breast he sees that she is pregnant with twins. The warlock's request is simple: knowledge of what the Pastor discussed with Redferne and Kassandra, in exchange for the unborn children's lives.
Kassandra and Redferne make it to the cemetery. Redferne jabs the weather vane into the ground, and it starts to shake from the warlock's blood which is still on the sharp barb at the vane's top-- a sign that the ground is consecrated and the warlock cannot tread on it. Still, he needs to know the pages are there, and therefore protected. The Pastor had told Redferne to look for a grave with a hex mark which will show where the final part of the Grimoire is buried. Kassandra finds the marked grave, but covers the inscription with her arms and tries to stop Redferne from looking. Suspicious, he pushes her away, and stops in sick horror on finding his own name-- Giles Redferne-- inscribed on the tombstone.
Kassandra is following Redferne out when she notices several empty grave lots and signs of digging and construction. She follows it to a sign partially obscured by bushes. She pushes them aside and sees it is a notice about the cemetery being remodeled and graves being moved as part of a project to modify the cemetery's layout in order to accommodate a building project for new condominiums. Alarmed, she tells Redferne about the sign and explains that maybe the remodeling projects means that Redferne's grave was relocated as well... and that the ground there is not part of the original cemetery, and therefore not hallowed.
Kassandra uses the weathervane as a gauge... and finds that the ground where Redferne's grave has been moved to, is indeed not consecrated... meaning the warlock can go there and open the grave without fear. He looks toward the grave with an expression of dread-- clearly the thought of seeing his own remains terrifies him.
Kassandra takes on the task of opening Redferne's coffin herself. She finds a skeleton inside clutching a sheaf of paper. The fingers of the skeleton are clasped around the last part of the Grimoire in such a way that she is forced to break them off in order to free the papers. Redferne, very impatient, accidentally turns around and recoils in horror.
The two are on their way out of the cemetery when the Warlock appears, flying at them and levitating over the ground. Redferne hurls the weathervane like a spear, but the Warlock dodges it, and it goes flying off into thick brush. Redferne separates the papers into two stacks, giving Kassandra one half, saying they should split up in hopes of keeping the Warlock from reclaiming the entire Grimoire. But the Warlock is too smart for this. He corners Kassandra and tortures her, pulling off her sneaker and slowly driving a nail into her foot, sarcastically thanking Redferne for giving him the idea. He digs the nail in deeper to make Kassandra scream in agony, and tells Redferne that he will make her suffer far worse than Marion ever suffered, unless Redferne emerges from the safety of the consecrated ground and hands over the last pages of the Grimoire. Redferne points out that far more than just Kassandra's life is at stake, and the Warlock scoffs, saying that only the truly daft believe in the stories of the "Uncreation." He issues a final ultimatum for Redferne to surrender the pages.
Redferne puts the pages down on the ground, putting a small stone over them as a paperweight, and challenges the Warlock to fight him hand to hand, no spells or magic, to claim them. He answers the Warlock's retort that he gives up nothing, by pulling out his own weapons and throwing them to either side. The Warlock begins producing witchfire that dances between his hands, and Redferne slyly suggests that without his magic, he is afraid. But afraid or not, the Warlock steps forward and he and Redferne fight hand to hand. Redferne starts to gain an advantage when he pushes the Warlock's head down onto the consecrated ground, burning him. Deciding that two can play that game, the Warlock answers by pushing his hand against Redferne's face and sending a bolt of witchfire right into his mouth. Kassandra grabs Redferne's whip and tries to garrote the Warlock with it, but he belts her with a stiff backfist punch and hurls her into the river bordering the cemetery. Redferne makes a last rush, but the Warlock uses his magic to throw Redferne back, where he lands right atop his own coffin and looks, up close, at his own remains, causing him to scream in utter terror.
Kassandra is starting to climb onto the riverbank when she stops, tasting something on her tongue. Fumbling with her purse, she grabs her insulin needles and climbs back down into the river.
The Warlock triumphantly gathers up the last pages and recites a dark chant that causes all the pages of the Grimoire to reunite and form a complete book, which cracks the ground it lands on. A storm begins to break as the Warlock commands the Grimoire to reveal to him, the hidden name of God. Lightning flashes down and strikes the Grimoire, and invisible markings become visible, snaking and twisting into lines that form into letters spelling out a name (Rokisha or Roaisha, for those who are curious).
As thunder begins to rage, the Warlock cries out in triumph, shouting to God that he knows Him now; knows His true name-- the word that can undo all that He has wrought. But before he can shout the name out and pronounce it backward, Kassandra jumps on his back, clapping her hand over the Warlock's mouth, and jams her insulin needles into his neck. The Warlock easily throws her off with a hitch of his shoulder and pulls the needles out... and Kassandra triumphantly shouts for him to "Try saltwater."
The salt in the river water injected into the warlock's body begins to destroy him from the inside out. His death-throes and agony are so great he cannot shout out God's name in reverse. He catches fire and burns alive in mid-air, finally sinking to the ground as a charred corpse. As Redferne stands over the corpse, the skull suddenly begins to move as if to make one last effort at achieving the Warlock's goal, but Redferne raises a booted foot and stomps powerfully down on the skull, crushing it into dust.
Redferne thanks Kassandra for her heroism, saying that he is in her debt. He seems to be leaning in as if to kiss her, and Kassandra closes her eyes and slightly puckers her lips. But a light breeze blows over her, and she opens her eyes to find Redferne gone, and a small funnel of whirling air moving slowly toward Redferne's grave, where it adds to the writing already on the tombstone, "I will remember you always 'til time and times are done." Kassandra is visibly moved by the new inscription, but then happens to turn and spot the Grand Grimoire, still lying on the ground, and she says, "Oh... shoot."
Cut to Kassandra burying the Grimoire in what appears to be snow... all around, is pure white. However, she is wearing only a light white tank-top shirt and no jacket, showing the weather is warm. She finishes burying the Grimoire and puts her shovel back into her car, then gets in and drives off, cheering. The camera pans out to show a large sign that reveals the location-- and resting place of the Grand Grimoire-- as the Bonneville Salt Flats in northwestern Utah... the world's largest deposit of natural salt.