Sam and Dean are contacted by one Adam Milligan who claims to be John Winchester's son. The boys immediately suspect a demon trap and go to investigate. Adam turns out to legitimately be John's son and Dean is furious that John kept Adam's existence from them as well as sheltered Adam from the hunting life. Meanwhile other supernatural forces are at work, which lead to a tragic twist that neither Sam, Dean, or their new sibling could have guessed.
Sam and Dean receive a phone call from Windom, Minnesota, from a teenager that wants to contact John Winchester. They drive to meet Adam Milligan that claims to be John's son and he tells that his mother has been missing for three days. The Winchester brothers discover that their father had traveled to Minnesota in 1990 to investigate a case of missing bodies and the two next pages of his journal are torn out. Furthermore, there are three corpses missing in the cemetery and the police believe that hooligans are responsible.
- Late at night, a woman runs from something in her house. She slams the bedroom door and something pounds on the other side. It stops and she blocks the door with a wardrobe.
She backs away and tries to calm down. We see her feet from under the bed. Closer. Closer.
Two hands grabs her and drag her under the bed. She grabs onto the nightstand and it falls over. A framed picture of John Winchester falls to the floor.
Dean (Jensen Ackles) wakes up in the car, starving. They're two hours from anything, Sam (Jared Padalecki) informs him. A phone rings. It's the John phone in the glove compartment. Dean answers. It's someone calling for John, Adam Milligan. He says John knows him. Dean tells him John died more than two years ago. Adam (Jake Abel) says he's his son.
Windom, Minnesota The boys pull up to a diner. Sam says Adam Milligan is real. No father listed on the birth certificate. He's a bio major at the University of Wisconsin. As Sam recites the info, Dean loads up from the trunk. He thinks it's a trap. He pours holy water in a glass and puts it out for Adam. If he's not possessed, Dean says he's a shapeshifter. Dean lays out the silver for his utensils. He's not pleased he used their dad as bait.
Sam tells him there's an entry from John's diary in which he says he's heading to Minnesota for a case. Nine months before Adam was born. The next two pages are ripped out.
Adam walks in. Sam and Dean say they worked with John. He thought John was a mechanic. Adam drinks some holy water. Nothing happens. Dean takes a gun under the table as Adam explains that his mom is missing. He says he didn't know his dad until he was 12. John drove to meet him as soon as he heard. Dean aims his gun at him under the table as Adam picks up his silverware and nothing happens. He talks about John having a 1967 Impala.
Dean can't take it anymore. He calls Adam a liar and says they're John's sons. Adam can prove it.
At his mom's house, he shows them a picture of him with John at a baseball game. John was there for a few of his birthdays. Sam compares the date. The entry says Minnesota. Dean's pissed that he took him to a baseball game. They ask more about his missing mom. Dean sees a picture of John and Adam's mom, Kate, smiling.
Dean and Sam check out the house, which has several smiling photos of John doing dad and family things.
Dean says maybe the cops missed something. Adam doesn't understand what Dean, who he thinks is a mechanic, might add.
Sam found a news report of 17 grave robberies in 1990. His dad is in the background of the photo.
Last month, three bodies from the local cemetery went missing. In addition to Kate (Dedee Pfeiffer), a bartender named Joe Barton is missing.
In Kate's bedroom, Dean notices Kate's fingernail scratches leading to under the bed. They take off the mattress. There's an airvent. Sam's rock beats Dean's scissors and into the vent he goes, cursing himself for not throwing paper.
Gun in one hand and flashlight in the other, Dean scoots along. He turns a corner and finds blood and guts everywhere.
Back at their motel, Adam barges in, wanting to know who the hell they are. They told him to call the cops but leave before they show. He sees the shotgun Dean's trying to hide. He knows they're not mechanics.
Sam says they're hunters.
Cut to later, Adam processes that every movie monster, every nightmare is all real. Adam says OK. They're his brothers, he believes them. When he asks if they think if his mom might still be alive, their silence answers.
Adam wants to help. Sam's all for it, but Dean shouts a lot. He wants to respect their dad's wishes. He storms out. Sam decides to teach Adam a few things. He hands him a gun.
Dean poses as Agent Nugent and inspects a cemetery. He finds embalming fluid on a nearby gravestone. The corpses were opened up.
Dean goes to the local bar to ask about the bartender. He ends up talking to his wife Lisa (Heather Feeney). He's been gone two weeks. Joe was a deputy a long time ago. He worked the grave robbery case in 1990. He found the bodies. His wife says he had help from a specialist.
Back at the hotel, Adam asks how their dad died. Sam tells him Dean killed the demon who got him. The lights go out and they hear noises in air vents.
Sam goes to inspect with a shotgun then they run to Adam's truck. Something grabs Sam and starts to drag him under the truck. Dean pulls up just then and blasts it.
Adam moves his truck and they find a sewer grate underneath. It's opened and there's some ooze around it. Dean winged it. They think it wants revenge against John.
They go back to Kate's house so Adam can get his stuff. Dean wants to take Adam to Bobby's and then come back. Sam suggests they use Adam as bait. Adam walks in and says he'll do it.
Out in the woods, Sam tries to teach Adam to shoot. Annie Oakley, he's not. Dean rolls his eyes. Sam teaches Adam about demons. He says being a hunter isn't a job, it's a life. He can't be close to anyone because they'll be in danger. He can only count on family.
Dean asks to talk to Sam, then calls him on quoting their dad to Adam, the speech John gave Sam before he went to Stanford. Sam now thinks their dad did right by them. Dean thinks Adam has a chance at a normal life.
Sam talks about the fact the world is coming to an end and the fact Adam being a Winchester means he's cursed. Dean resolves to look harder for the thing.
He goes back to the cemetery. He looks around a tomb with his flashlight. He sees a cobweb blowing in a hidden breeze. He knocks out a brick from the wall and finds a tunnel. Time to do his best John McClane impression again.
Dean crawls. He reaches a room with bodies and bones laying around. He finds a fresh arm and Joe's glasses. He hears a noise coming down the tunnel and shoots at it. The tunnel caves in. And guess who has no cell reception? He's trapped.
Sam fortifies Adam's mom's house, closing off every way in with salt except the bedroom vent. They hear a woman's voice downstairs. Adam runs to his mom. Sam warns him to step away, that it's not his mom.
In his tomb, Dean opens a coffin and finds bloody, soggy Kate.
Back at the house, Adam takes Sam's shotgun. Sam urges Adam to kill his not-mother.
He says she's not human. Adam smiles. "I know," he says as he coldcocks Sam with the gun butt.
Dean opens another coffin. It's Adam.
Dean realizes what this means and tries other ways to get out.
Sam wakes up, tied to the bed. No wonder the silver didn't work, he says. They're not shapeshifters, they're ghouls. They are what they eat, taking on the shape and memories of the last person they killed. Kate slices Sam's arm and takes a lick. She thinks his blood tastes different.
Dean moves some coffins to underneath what turns out to be a stained glass window. He bashes it out and climbs out.
Not-Kate and not-Adam explain Sam's dad killed their dad, as they slice him and poke him. They're going to feed on him nice and slow, just like they did with Adam. He really was their brother, they tell him. They slice Sam's arms open. He starts to bleed into bowls.
Dean busts in and shoots Adam in the chest. Sam tells him they're ghouls and he blasts Kate's head off, the only way to kill them. Before he can untie Sam, Adam pounces. As Sam bleeds, Dean beats the living (dead?) tar out of Adam, crushing his head.
He gets Sam up and helps to slow the bleeding. "That's what family's for," Dean says.
At the cemetery, Dean prepares Adam for a hunter's funeral, burning his body.
Dean finally gets why Sam and their dad butted heads so much, they're practically the same person, he says. Sam decides to take it as a compliment. "Take it any way you want," Dean says.