Sam Nozik's beetles-eaten corpse in a Florida glade is identified from his acrylic eye. He worked in a Miami museum, from which a treasure map to a Spanish galleon was stolen. Booth grudgingly allows his superstitious former foreign army tour acquaintance Walter Sherman (and his team of two) to use his 'tracing gift' to find and retrieve the treasure. They do, after consulting bishop Edward Galano on period navigation, and find the corpse, but meanwhile the diver herself has been murdered too. Booth meanwhile comes to terms with his grudge against Walter as 'insensitive' MP.
The remains of a maritime museum security guard are found in the Florida Everglades after an attempt to steal an obsolete 17th century nautical chart fragment used to find treasures. In order to solve the crime, Booth seeks out Walter Sherman, a former Iraqi soldier with an uncanny gift to unearth anyone and anything. With Sherman's help, as well as that of his colleague, Ike Latulippe, and his legal advisor, Leo Knox, the team is led to tattoo artist who points them in the direction of a tough young woman. But when the woman is found murdered with remnants of the map lodged in her remains, the team discovers centuries of history linked to the map and the suspect behind the crimes. Meanwhile, Brennan puts Sherman's remarkable skill to the test, and Booth harbors cold feelings toward his former military comrade.
- Welcome to Florida, where Bones (Emily Deschanel) and Booth (David Boreanaz) find remains in the middle of the Everglades. Bones finds a fake eye with a discernible serial number. The partners trace that number to a security guard at a nearby museum. B&B interview the curator, who shows the investigators footage of the guard, from days earlier, acting mighty suspicious around a certain exhibit. That exhibit is an unauthenticated map supposedly leading to a sunken treasure ship. The dead guard apparently took a fragment of said map. "Find the map, find the murderer," Booth suggests.
Later, Booth and Bones visit a too-perfect bar in the Everglades to recruit a former wartime colleague of Booth's who the FBI agent claims has "finder power." The man, Walter (Geoff Stults), is immediately skeptical and asks to see their credentials. Booth is annoyed. B&B also meet Ike (Saffron Burrows), the bartender, and Leo (Michael Clarke Duncan), Walter's "legal advisor" before Walter takes Bones' ID. Booth tackles the man. They tussle like the old friends they are. Ike shugs, telling Bones the two are only "getting reacquainted."
The "fight" ends. B&B show Walter the security video. He immediately spots that the guard has a fake eye. Bones is impressed. "Are you two sleeping with each other?" Walter asks. B&B say no. "Will you sleep with me?" Walter asks Bones. Booth scoffs, but Bones appears strangely interested. Walter then agrees to find the map as long B&B agree to catch the killer. Deal. As B&B exit, Bones doubts Walter's "finder power." He is insulted -- and challenges Bones to name something she lost. She explains she long ago misplaced a medal from a grade-school science fair. "That's all I need," Walter says.
CUT to Walter, Leo and Ike, who visit the security guard's cheap apartment. Walter announces he is going to break into the pad. Ike and Leo, meanwhile, have a chat in which it is revealed Walter saved both their lives. So they owe him. Inside, Walter strips down to his undies and makes himself at home. Apparently, this is part of his "process." He soon finds a stack of crime books in the bathroom. Inside one of the books is the receipt from a pawn shop. Interesting. Suddenly, Walter's cell phone rings. It's Bones. Walter suggests the victim was a). terminally ill and b). tortured for the location of the map before he died. Bones, who is examining the remains, is astounded. That's exactly right. Walter got all that from just examining the man's apartment.
Walter either has second sight or he is tremendously lucky as the only clue to the guard's health condition was ancient pyramids above his bed -- apparently a sign he wanted to fall asleep looking at something ageless. CUT to Ike, Walter and Leo, who stakeout the pawnshop. They eventually head inside to reclaim the item: a smashed ukulele. The clerk says a woman with a tattoo across her chest reading "Do not resuscitate" (ouch) smashed it before taking a slip of paper from inside. CUT to a tattoo shop, where Walter asks the assembled crowd if they know of a woman with such distinctive tattoo. A GIANT biker demands to know why they're asking -- and SLAMS Walter against the wall then the "finder" suggests he is a meth dealer. Leo, hardly a little man himself, steps in and quickly dispatches the biker with a few well-placed punches.
Later, the gang visits a bar where they immediately spot Brittany, the girl with the tattoo. "Looks like the biker didn't lie to Leo," Walter observes. He then suggests he'll distract Brittany while Ike breaks into her car and looks for the map fragment. Brittany leaves the bar and heads to a dock where she has a boat called the "Screw You." Walter follows and notices a telescope on the deck. Brittany explains it belongs to her client -- and that if today goes well, she'll never return. Somebody is going treasure hunting. So Ike and Walter head out in a plane (did we mention that Ike can fly planes?) in search of the "Screw You." "The chart fragment has got to be on that boat," Walter said. But where is the boat? And who is Brittany's client?
Sometime later, Walter shows up at the Jeffersonian ... and hands Bones her science-fair trophy. Bones is astonished -- again. She also begins to tear up as Walter has also located a local newspaper story with a picture of Bones' mom. "I like to impress you," he says. Walter then visits Angela (Michaela Conlin), who is recreating the map fragment from the video footage. Sure enough, clues on the map indicate the "Screw You" is heading to Key West. Moments later, Walter, Ike and Leo are riding on a boat to the location. Walter dives into the water and finds Brittany's dead body.
CUT back to the Jeffersonian, where Bones and Camille (Tamara Taylor) examine Brittany's body. They find something jammed in her throat. It's the map fragment. They also find a finger. Brittany bit off the finger of her client before she was drowned -- and had the map fragment shoved down her throat. Walter spots blood on the map and rubs it. An "X" appears, though no one notices but him. Walter then hands Booth a stack of receipts so he can be reimbursed. The map fragment has been found, he says. "My job is done." B&B will have to find the killer on their own.
Later, Walter and Ike visit Bishop Galano, who is an kind of expert on Vatican treasure ships. Galano and Walter are old friends, though Walter clearly isn't a religious man. Galano explains an invisible ink of sorts was used that responded to blood. Three nails on the map indicate its creator was a Jesuit, which would mean he would've measured longitude from a different point -- the Copernican Observatory. They've been incorrectly reading the map. Brittany's killer likely did the same, killing her when they arrived at the wrong spot. Galano then brings up a touchy subject. "I wish to discuss the brain damage you suffered in Iraq," he says. Walter storms out.
At a nearby café, Ike then suggests Walter is scared of losing his "finding mojo" if he were to be treated for his obvious mental problems. "You call it paranoid, I call it epiphany," Walter explains to Ike. Back at the Jeffersonian, Hodgins (T.J. Thyne) has noticed the three nails -- and tells Booth he can find the treasure. Booth is intrigued. He also realizes that Walter is no doubt far ahead of them, too. Sure enough, Walter visits the museum curator, Lambert Chaisson (Carlo Rota), ... and presents a Madonna statue from the wreck. The curator is thrilled -- and then reveals his hand is in a cast. He is, in fact, missing a finger.
"You're not the police, so what do you want?" the curator asks. Furious, Walter PUNCHES the curator, explaining he wants Brittany back. CUT to B&B. Booth suggests arresting Walter for stealing the treasure. Turns out, years ago, Booth went AWOL to get to the birth of his son. Walter was sent to find his fellow soldier and arrested Booth in the delivery room. So Booth is bitter. Suddenly, a van pulls up. Ike is driving with Leo in the back. Leo shoves a giant trunk out into the sidewalk. It's not the treasure, though -- Walter, on the advice of his legal advisor, has returned the treasure to the Catholic Church. Instead, the trunk contains a grunting curator. "It's a fine line between kidnapping and citizens arrest," Leo explains. Case closed.