|Angela has split with her boyfriend, Matt, and has gone to her friend Neil's house for chocolate and sympathy. While she's there, Matt turns up and while he and Neil are arguing at the front door, Angela heads out the back door and drives off. Matt phones her while she is driving, but she loses control of the car and crashes it. She dies instantly. Meanwhile, Sam wants to go and say goodbye to their mom, visiting her headstone but Dean cant understand why. He agrees to go with, and while Sam is burying John's dogtags near Mary's headstone, Dean notices a strange pattern around Angela's recently buried body. The grass and trees around the grave site have all died completely. Dean thinks the ground there is unholy for some reason, but Sam thinks he's simply avoiding thinking about their parents. They agree to go and talk to Angela's father, but can see nothing unusual.
After a minor argument between the boys, Dean leaves and breaks into Angela's apartment to have a look around. He is spotted by Angela's roommate, Lindsey, and convinces her that he is Angela's cousin. She reveals that Matt is also dead - he apparently slit his own throat - and Dean notices that Lindsey seemed more upset about Matt's death than Angela's. Sam and Dean decide to go and talk to Neil, posing as counsellors from the college. He tells them that Matt was sleeping with someone else behind Angela's back, which is why they split up.
Believing that Angela has come back as a vengeful spirit, Dean and Sam go to dig up the body and burn the bones, but they get there and discover that the coffin is empty. Dean notices some symbols carved into the coffin, recognising them as similar to ones he saw on a book in Angela's fathers office earlier. They confront him, with Dean accusing him of raising his daughter from the dead, until Sam realises that it couldn't have been him - there is no sign of any decaying plants or anything in the office. They leave, with Sam unable to understand why Dean got so angry and upset.
They investigate ways of destroying zombies, but decide that they need to find the person who raised her first. Dean thinks it might be Neil,so they head to his house. When they get there, no-one is home and they sneak around, having a look. They suspect that Angela was there, but she has escaped. She's gone back to Lindsey - the person Matt was cheating with. They get there in the nick of time, saving Lindsey from the zombie Angela, who ran off again. They finally confront Neil, telling him that they have a plan to destroy Angela. She overhears and is lured back to her gravesite, as Dean and Sam anticipated. They manage to trick her, making her fall into her coffin again, so they can stake her into it, finally destroying her.
They leave but on route out, Dean stops the car. He wants to apologise to Sam for the way he's been acting. He's realised that somehow John sacrificed himself to bring Dean back to life and he can't come to terms with it. He believes he should never have come back - the dead should stay dead - and the thought is killing him.