The title and credits are shown with a book titled, "a true story of a flying saucer" over a cloud filled sky. Artie starts to tell us his story as narration as he turns each page of the book. We open at night after a rain storm in front of the Larkin farm house. Artie continues his story. A car drives by on the way to Lover's Point on the Larkin property. Farmer Larkin (Raymond Hatton) runs out holding a shotgun. "I'll get the law after them," he mumbles. The town is called Hicksburg and it is Saturday night. Two drifters are eating and drinking at a Diner. Joe Gruen (Frank Gorshin) and his partner Artie Burns (Lyn Osborn) finish their meal. Joe tries, unsuccessfully, to pick up the waitress (Jan Englund). Artie tells Joe they are leaving town the next morning. Joe decides to borrow the car and try his luck elsewhere. Artie decides he'll walk back to their room at the boarding house. As Joe drives he sees a flash of light and a spaceship cruise across the sky and land in a clearing by the road. He drives the car to that clearing, exits the car, and wanders towards the craft.
Back at the Soda Shop, a group of teenagers see the same flash of light coming from the Larkin farm area. Johnny Carter (Steve Terrell) asks, "What the heck was that?" His buddy replies, "A bolt of lightning." The third friend, Duke (Jimmy Pickford) observes that there are no clouds in the sky. Inside the shop the soda jerk, Jack (Bob Einer) asks Lt. Wilkins, USAF (Douglas Henderson), "Well how's the recruiting coming along, Lieutenant?" "Not bad," is the reply. Jack walks out to see what the three boys are talking about. He is told that Duke claims to have seen a blue flying saucer. Wilkins comes out and Jack tells him the boys claimed to have seen a flying saucer. Lt. Wilkins visibly responds, then resumes his composure and quickly leaves. Joan Hayden (Gloria Castillo) pulls up in her old car and greets her boyfriend, Johnny. They have a date, but her father doesn't approve of Johnny, so Joan lied about who she was seeing. They get in Johnny's newer car and head for Lover's Point. Like everyone else they cruise by Larkin's house slowly and with the lights off as not to alert Larkin. Larkin does hear them. Lover's Point is busy tonight. They stop to neck.
Joe sees something at the UFO site and retreats into the woods. He gets in his car and drives away. At the Point, a bull named Old Walt, disturbs a couple in their car. The woman screams and her boyfriend throws the animal a can of beer. We learn that Joan and Johnny are eloping tonight. Joe makes it back to the room. He wakes Artie from a sound sleep to tell him about the spaceship. He is excited, "We're millionaires." He tells Artie he saw a flying saucer and they are going to cash in on it. Artie thinks his friend is either drunk or crazy, or both. He goes back to sleep. Larkin's bull enjoys another beer. Johnny shows Joan the ring he bought for her. Lt. Wilkins waits for Col. Ambrose, USAF (Sam Buffington) to get dressed. They are to take a small group of airmen to investigate the UFO. The Colonel directs Wilkins to get some of his men and have them load their weapons. Johnny and Joan drive off to get married. They drive with the lights off and nearly hit a Jeep carrying the Air Force Personnel. A flash of lightning and the slick road causes Johnny to hit a small creature that darts out in front of his car. They get out of the car to investigate. At first they think they've hit a child, but another flash of lightning reveals a large headed alien about three feet tall. Joan is repelled and she demands, "Get me away from here." The creature's hand was severed during the collision and with its eye guiding it, creeps over to the front tire of Johnny's car. With needle like claws it punctures his front tire. Unfortunately Johnny has no spare so they decide to walk to the Larkin house and call the police. The hand crawls off.
The Air Force arrives at the clearing and spots the UFO. The Colonel decides to call division headquarters to get engineers on the scene. Joan and Johnny arrive at the Larkin house. They knock, but there is no answer. They let themselves in and use the telephone. They call the police, but the Desk Sergeant does not believe their story. Another flash of lightning corresponds with a power outage. Joan finds and lights some candles. Joe drives past Johnny's car and notices the small body wedged under the bumper. He tries to move it, but it is a bloody mess, and wedged in tight. He takes a swig from his bottle. Joan sees something outside and runs to Johnny. At that the lights come back on and they see Larkin at the front door holding his shotgun. Larkin demands to know why they are in his house. They tell Larkin that they hit something. Larkin assumes it was one of his animals. Larkin tells them he is going to call the police, but Johnny tells him the phone is dead. Larkin smells the strong scent of alcohol and accuses the teens of drinking. Larkin calls the operator and tells her to get the police out to his place. He leaves the house to check on his livestock.
Joe throws a blanket over the alien body and again tries to move it. He takes another drink. He gets in his car and drives away. Johnny and Joan walk back to their car and hear a strange sound. Joe stops at the Larkin house to call Artie. Finding the place empty he helps himself to the telephone. Artie answers and listens to the story, but does not believe it. He does empty the refrigerator per instructions because Joe tells him he's bringing home something perishable. "We got to keep it on ice," he tells his roommate. Joe drives back to Johnny's car as Artie empties the refrigerator. Before going to bed he stuffs cotton in his ears so he won't be disturbed by another phone call. Joe makes one final attempt to retrieve the little alien body. He needs a stick to pry the body out, so he ventures into the woods. The aliens are waiting. With their alcohol venom they repeatedly sting Joe. Four little aliens carry Joe's body away. Johnny and Joan approach Johnny's car. They hear a strange pounding and move closer to investigate. They spot an alien with a jackhammer pounding on his car fender. Johnny assumes they are stupid and primitive and are mad at the car for killing their little friend. He doesn't learn until later they do have a plan.
At the UFO site, the USAF personnel surround the craft. They get no response from a Sergeant with a bullhorn (Scott Peters) repeatedly hailing the occupants. Johnny and Joan leave his car and walk away, but upon hearing a police car siren decide to go back to the car. A corporal fires a few rounds at the UFO. All shots bounce off the spaceship. The Colonel orders it be cut open with acetylene torches. By the time Johnny and Joan arrive at his car, the police have already loaded Joe's body into an ambulance. The Detective (Jason Johnson) takes Johnny's statement. They describe the alien, but the detective only knows about Joe, so he assumes the kids are drunk. He gives Johnny a field sobriety test with "the balloon." He calls the doctor (Russ Bender) over to discuss the story. They are disgusted by the whole thing and the apparent callous response to killing a man. They also note the strong smell of alcohol. Johnny is anxious to leave. The confused detective asks, "For a guy who has committed a serious crime, you're awfully anxious to get to the police station."
At police headquarters the detective finishes typing up the report. He hands it to Johnny to read and sign. Johnny realizes something is wrong and refuses to sign it--it is not a report but a confession to murder. Joan demands her father, the city attorney, be called. The detective, anticipating that, tells Joan he's already been called and is due shortly. Mr. Hayden (Don Shelton) walks in and picks up part of the conversation about beating a confession from Johnny. Hayden tells her that he'll try to get her out of the mess, but Johnny's on his own. They go down to the morgue to identify the body. Johnny and Joan are expecting to see the little alien body, but the detective knows it is Joe Gruen. Surprised, Johnny explains, "I didn't run over this man." Hayden asks to talk to the kids alone. He tells Johnny, "Now get this, both of you. We're lucky in one respect. The man you killed is a nobody. There will be only one person interested in the charges brought against you. That's his roommate."
At the UFO site, the engineers begin to work on the spacecraft. A pair of engineers are trying to cut the craft open with torches. When they get to a seam, the metal ignites like a fuse and the craft explodes. The blast lights up the sky and the sound carries for miles. The police see it and send a car to investigate the Pelham Woods area. Johnny finally figures out the alien plan to frame him for Joe's murder. Johnny and Joan decide they need more evidence so they leave through the open window and take the detective's car. They drive the police car back to Johnny's car. They search the woods and are being watched by the aliens. The police car dispatched to check on the explosion encounters an Air Force Jeep. Wilkins tells the officer, "Everything's under control officer. One of our jets crashed." The police drive off. Johnny and Joan walk back to the police car. The crawling alien hand scales the car and enters through an open back window. It falls onto the back seat. Johnny and Joan drive off. Joan is cold, so she reaches back to close the back window. The hand begins to scale the back seat towards her. As they drive to the Point to tell the other kids, Joan spots the needle like claws on the hand. She screams and they jump out of the car and close the doors. Now they have evidence. They decide Artie would be their best witness.
The Air Force cleans up the site. Johnny and Joan tell Artie the story. "Killed by little green men? That is the craziest story I've ever heard," Artie replies. At their insistence, Artie calls the police to verify part of the story. The Desk Sergeant tells Artie his roommate was killed and they are looking for the boy and girl who killed him. They managed to escape custody. Larkin's bull encounters an alien. It attacks the already drunk animal, but the bull doesn't go down without a fight. Artie brings a camera and a gun. They take Joan's old jalopy. The three drive back to the police car. The little aliens are already there and are trying to open the police car to get the hand as Johnny, Joan, and Artie arrive. The three spot the hand on the floor board. Artie takes a picture with a flashbulb. As he does so, the hand disappears in a flash of smoke. With picture in hand they decide to drive Joan's car back to town. But Joan's car battery is nearly dead. With no lights to keep them at bay, the aliens approach their car. Artie fires at them. They conclude that lights hurt them. With the battery now dead the aliens come closer. They run for it, but Artie is attacked and stung. Johnny and Joan take a flash picture to distract the aliens and escape. They decide to call the police again from Larkin's farm. Johnny tells the police they are ready to surrender. The detective tells him that he is no longer wanted. He explains that Joe died, "As a result of heart failure due to alcoholism." He further explains that Joe was hit after he died. As for the stolen police car, that was recovered by the team sent out to the UFO site, and the legal matter was handled by Joan's dad. With no other avenue, Johnny and Joan decide to seek help from their friends at Lover's Point. Larkin finds Walt very drunk. He is furious. Going from car to car, Johnny and Joan tell their friends the story. They drive off to a clearing. The aliens are carrying Artie's body to the same location. The plan is to surround the clearing and upon a horn signal all will turn on their car lights to burn the aliens up. They arrive and turn on the car lights. The aliens squeak and squeal. They start smoking and disappear in a flash of smoke. Artie wakes up very drunk. Johnny and Joan explain to him what happened. Johnny concludes that the aliens poison their victims with alcohol. If a person is already drunk then the attack raises their blood alcohol level to a lethal range. Larkin shows up at the clearing, fires a few shots into the air, and tells the kids to get off his property. Artie is taken to a car by two beautiful young women. He begins to finish his story narrative, "So that's my story. Johnny and Joan helped me remember a little of it. But I wrote it you understand. A true story? Well that's the nice thing about all this book writing business. You pay before you read." We close with the alien hand closing the book and a scream.