Sam and Dean break into a house and find a corpse on the floor, covered with a sheet. The rest of the room is covered in blood and there's no ID on the body. They figure that they missed whatever happened but Sam points out a laptop computer with a post-it note saying "Play Me". They do and the words "This should never have ended this way" come up.
The brothers watch as a college student, Brian starts filming in a diner...
Brian tells his friend Michael that he doesn't know what to make his movie about. Michael takes the camera starts goofing off with the camera and Brian grabs it back. They notice some girls nearby and Michael suggests that one of them might take sympathy on Brian. As Brian films them, one of the girls, Kate, comes over and asks if they're filming her. She knows about the camera technology and flirts with Michael.
Later, Brian sits in the house and listens to Kate and Michael making out in the next room. Kate passes through later on her way to the kitchen."
Brian, Michael, and Kate go back to the diner and Brian ends up talking about cameras with Kate. She assures him that she's teaching Michael how to use cameras.
Kate talks about what she plans to do in five years as she sits on the couch with Michael. Brian figures that he'll be working in the film industry, and Michael plans to be on a boat in the middle of the ocean.
Kate, Michael, and Brian attend a class by Professor Ludensky on Lord of the Flies
. Michael sleeps through it and afterward Kate tells him what he missed. Brian assures him that he taped it for him and then a guy runs by, bumping into Michael and knocking the camera to the ground. The trio go after them and watch as the police take away a murder victim two blocks away. Sam and Dean arrive at the scene, posing as FBI agents, and the detective in charge tells them that the woman heard a neighbor, Jacob Carter, scream followed by some kind of growling noise.
Back at the house, Brian tells Kate that it's good that the FBI are there. Michael comes out and plays the song that was at the diner when they first met. He then heads out with Brian to test the new cameras, and secretly tells Kate that he's going with his friend because Brian doesn't have anyone else.
The two friends go to the stadium and film some footage, and hear Dean and Sam nearby. Dean insists that there's a case there and they just have to dig a little deeper. As night falls, Brian and Michael spot a couple making out near the bleachers. The guy is Scott Parker, the man who knocked Brian over earlier. The girl finally pulls away and walks off, and the guy spots the two friends. They run off in separate directions and Michael hears something moving in the woods. It comes after him and he screams. A few minutes later, Brian comes looking for his friend and finds Michael on the ground, gasping for breath. His leg has a large bite wound in it and Brian takes him home. However, the bite mark is missing and Kate wonders if they punk'd her.
Later, Kate and Brian bring Michael back from the doctor. The doctor said that there's nothing wrong with him. Once he wakes up, Michael gets off and pulls open a door, and rips it off its hinges. Michael demonstrates his newfound strength, lifting Kate into the air one-handed. He wonders if he's become a superhero.
Brian places cameras throughout the house and Kate catches him at it. He explains that he's going to get Michael's origin story on tape and proceeds to tape him all the time. As Michael has a bagel, Brian says that he wants to do what he does and suggests that they go out there so he can get bitten and they'll both be superheroes. Michael objects, assuring his friend that there's nothing wrong with him, and insists that he doesn't want what he has. Brian begs him but Michael refuses.
Someone knocks at the door and Brian goes to get it. It's Sam and Dean, who ask Brian if he heard anything the night of Jacob's murder. They also ask if he's heard any rumors of someone getting bitten. When Brian says he hasn't, Sam gives him his card and leaves. As they go, Kate and Michael watch and Sam suggests that they might be dealing with another Mayan god. Brian checks with his friends and Kate plays back the tape she made. Michael wonders if he's now a golden Mayan god.
In the middle of the night, Michael gets up and goes to the bathroom mirror. As he admires himself in the mirror, Michael starts to grow fangs and films himself as claws grow out of his fingertips. He smashes the mirror and then goes back into the bedroom where Kate is sleeping. Michael strokes her cheek without waking her and then goes to the bedroom and starts wolfing down all the food they have.
Scott and his friends, Doug, Evan, and Tucker are out patrolling for the animal that killed Jacob. They film themselves as they go out and patrol the neighborhood. Scott finds Michael, who warns him off, and then drops a couple of sacks of garbage and runs off into the woods. When Scott chases him into the woods, threatening to go after Kate, Michael turns and attacks him.
The next day, Brian asks Kate if she's afraid of Michael. She admits that she was at first but since then it's been pretty hot. Michael comes in, covered in blood. He takes a shower to wash it off and tells his friends that Scott chased him and he killed the student. They look at the footage and see the claws, and Kate comes to her boyfriend's defense, telling Brian to turn off the camera.
Brian goes to the new crime scene where Sam and Dean talk to the detective. He figures that Scott was killed by the same thing that killed Jacob, and the heart is on the street nearby, partway eaten. Brian goes back to the house and tells Michael and Kate what happened. Michael says that he doesn't remember and Kate insists that it was self-defense. When Brian gets angry, Michael shoves him across the room and then breaks down, telling Kate that he doesn't know who he is anymore. Kate assures him that he's hers.
Brian says that they have to call the police and warns Kate that whatever Michael is, isn't good for him. She tells Brian that he doesn't understand because he's never been in love, and says that they need answers.
Kate and Michael follow Sam and Dean to the morgue. Sam tells his brother that ten years ago there was a series of similar murders but during the wrong time of the month. As they head off, Kate insists that they should follow them but Michael isn't interested. Brian follows them via the GPS in their phones and he assures them that he can hack into anything. They soon access the camera feed to the diner where Sam and Dean are working, and Michael goes in with a hidden camera and sits at the next table. The brothers find an entry about early-generation werewolves that are less feral, can transform when they wish, and can subsist on animal hearts. They figure that the werewolf killed someone ten years ago and then decided to stay.
Back at the house, Michael starts to panic and Kate points out that Sam and Dean aren't FBI agents. She figures that they're looking for the pureblood, not Michael, giving them some time to figure things out. Michael isn't satisfied and storms out, and Kate goes after him. While they argue, Brian reviews the footage of the attack on Michael and tells them that he found something, but Kate slams the door shut. Brian goes out on his own and finds a pin on the ground near the murder scene. It's the same pin that Ludensky was wearing in class. Brian goes to confront Ludensky at his office and tells him that he knows what he is.
Later, Brian comes home and finds Kate packing. He tells her that he took care of things as Michael comes out, and they ask what he did.
Earlier, Brian asks Ludensky to turn him into a werewolf and warns him that he's feeding the footage back to his laptop at home. When Ludensky denies it, Brian threatens him with a silver dagger. The professor finally explains that he tried to stay with animal hearts for ten years until he finally lost it when he saw Jacob, alone. Ludensky mentions the hunters and Brian says that they're here, and he realizes that Ludensky needed a patsy to misdirect them. He picked Michael because he sleeps through his lectures and figured that no one would miss him. Brian says that he wants to see what Ludensky sees and do what he does. He then holds up his arm, revealing a rapidly-healing bite mark.
Brian starts to transform and show Michael and Kate footage of Ludensky going berserk in his office and destroying the hidden cameras Brian put there. Sam and Dean come in and are forced to kill him. As he dies, Ludensky thanks them. The brothers find the camera and take it down. Brian tells his friends that they're in the clear and that he did it to protect Kate when Michael couldn't. Michael points out that the Winchesters saw the camera and figures that they'll trace it back to him. Brian chuckles and says that he's finally got what he wants and that he's sick of living in Michael's shadow. Michael insists that Brian doesn't want what's in him and that he remembers killing Scott and how he can't control himself. Brian tells Kate that she needs someone to take care of her and grabs her, and Michael transforms and attacks him. Brian stabs him with the silver dagger and Michael tells Kate that he loves her with his dying breath.
Once Michael dies, Kate tries to stab Brian, who insists that she'll understand once he bites her. She tries to run but he grabs her and bites her on the shoulder. She locks herself in the bathroom and films herself as she goes berserk, ripping the place apart. Finally she gets control of herself, tells Brian that she understands, and goes out. As he smiles, Kate bears her fangs and kills him. She covers Michael's corpse with a sheet and records a final message, explaining that none of them were monsters. Kate then says that she's leaving and they'll never hear from them again, and that she'll eat animal hearts and never hurt anyone. She begs whoever is watching to give her a chance.
Sam and Dean finish the movie and wonder what to do next. Much to Sam's surprise, Dean says that they should give Kate a shot at trying to live a human life. They collect all of the computer equipment and leave.
Kate hitches a ride out of town and walks away along the railroad tracks.