Twelve Years Ago
A cloaked hunter tracks a wounded woman through the forest. As his dogs go past her, the hunter himself finds the woman and decapitates her with his axe. Her necklace falls off as her body falls to the ground and the hunter takes it.
Sam and Dean head to Colorado to investigate a series of murders involving decapitations accompanied by local cattle mutilations. According to John's journal, a similar set of murders and mutilations occurred in Hoover two years ago, and all of the victims had moved to Hoover three years previously. While Sam looks for people who have moved from Hoover, he spots a cloaked figure in a passing SUV and thinks that he looks familiar.
Dean is waiting at the Impala and notices four kids atop a rooftop, taunting a fifth one, Ryan, into standing on the edge. The kids' leader, Charlie, dares Ryan to let go of the railing, saying he's as big a coward as his father Gayle. Ryan defiantly lets go of the railing and stands suspended in space, but loses his balance and falls three stories. Dean manages to catch him but Ryan complains of head pains. As the bullies run off, Ryan thanks Dean for his help. Dean tells him that he should learn to stand up for himself and starts to leave, but Ryan breaks into tears.
Dean drives Ryan home and explains that he was able to catch the boy because of the training that his father John gave him. Ryan explains that his father works at Charlie's father's farm and Charlie started picking on Ryan. He asks Dean if he could teach him to fight, explaining that his father travels a lot so they've had to move six times. Ryan doesn't remember his mother, who died in an accident when he was younger. Dean is hesitant to teach Ryan, but finally agrees to meet with him the next day as they arrive at the boy's home in the country. As they talk, Gayle watches them from the house.
That night, Sam and Dean discuss the case in their motel room and Sam confirms that the hunter in town is Jason, a ruthless killer. Sam tracked Jason to his camper on the edge of town, and Dean wants to keep an eye on him. However, he dozes off before he can tell Sam why he's so interested in training Ryan.
The next day, Dean takes Ryan to an abandoned factory and loans him his old judo ki as they train. As they spar, Ryan says that he wants to become strong enough to make things different in his life, and Dean wonders if he understands what he's talking about. The boy drops the matter and they fight, and Ryan loses control and slams Dean to the ground. Dean finally manages to subdue him and warns him not to let his emotions get in his way. Ryan tells his new found friend that he doesn't want to be like his father.
After young Dean kills a monster, John grabs him by the arm and pins him to the ground. He reminds his son that he trained him so that he could protect himself and others against monsters, and asks why Dean kept shooting even after the monster was dead. John warns Dean to never lose control because they use their abilities to protect people from monsters, and Dean says that he understands.
Dean tells his student that he never lost control again after that day and became stronger as a result. Ryan wonders why Dean is helping him and Dean wonders if Ryan is someone he has to protect. He also understands what Ryan is going through with his father since he hated John that day and wished he was dead. Ryan clutches at his head in pain again and passes out, and Dean drives him home. By the time they get there, Ryan says that he's okay. Gayle isn't there and Ryan explains that his father goes out after work most nights. Dean looks around and sees a photo of Gayle and his wife Miranda with their baby son Ryan. There is a discharged silver bullet on a plate on the table and Dean takes it with him. He calls Sam to say that he's staking out the place while Sam watches Jason at his camper. As he hangs up, Dean spots someone attacking a cow in a nearby field. Dean goes over and realizes that Gayle is killing the cow and drinking its blood. He calls Sam back and tells his brother that Gayle is a vampire. However, Gayle gets the drop on Dean and knocks him out. Meanwhile, Sam realizes that he's been tricked when he discovers that Jason has left a dummy in his place.
When Dean wakes up, he discovers that Gayle has tied him up and taken him to the hayloft of his barn. Gayle angrily asks if Dean is teaching Ryan to hunt his own father, and starts to kick Dean off the ledge onto the razor-sharp farming implements mounted below. Dean quickly explains that he knows what it's like to hate his father and lose his mother, repeating the words Ryan told him about how Ryan said that only a fool strikes back in anger. Gayle pulls Dean back and explains that he manages to live among humans by only feeding on animal blood. He and his wife moved from town to town to avoid detection but twelve years ago, Jason hunted them down. He killed Miranda while Gayle escaped with Ryan. The silver bullet was the bullet that killed Miranda. Gayle explains that Ryan doesn't know that he's a vampire, and that he planned to tell him once he was sure the boy could restrain his anger. However, he admits that once the headaches begin, there's no way to stop the awakening. Shocked, Dean realizes that he may have helped awaken Ryan.
At the nearby house, Ryan suffers more head pains.
Gayle asks Dean to let him and his son go, assuring him that he would never put Ryan in harm's way by attacking humans and risking exposure.
Ryan feels at his mouth as his incisors grow out, pushing the teeth above them. He hears a gunshot from the barn and goes to investigate.
Jason shoots Gayle repeatedly with silver bullets, crippling him. The hunter frees Dean and says that he's fine with killing another vampire, but Dean tries to explain that Gayle doesn't feed on humans. Jason doesn't care and prepares to torture and then decapitate Gayle with a blade soaked in the blood of the dead. Gayle sees the hunter wearing Miranda's necklace and struggles with him, and Dean snatches up a pitchfork and tells Jason to surrender. Jason kicks Dean down, knocks Gayle away, and prepares to shoot both of them. As he prepares to pull the triggers, Jason tells Dean that he's softer than John ever was.
Two gunshots ring out... as Sam arrives and cripples Jason. Gayle goes for the hunter's blood but Ryan comes in, now a full vampire, and begs his father to stop. He reminds Gayle that his father once said that only an idiot attacks out of anger, and that Miranda wouldn't want him to become a killer. When Gayle hesitates, Ryan says that he's protecting him from his anger just like Gayle has protected him. Gayle finally regains control and looks down at Jason.
Later, Sam and Dean head out of town. They figure that the father-and-son vampires will move on to another town. Dean admits that he wanted to teach Ryan the same discipline that John taught him.