During the investigation of a murder in Kearney, Missouri, in which a wife killed her husband for an incident from 30 years earlier, Sam and Dean run into fellow hunter Garth. They learn that Garth has stepped into Bobby's role, organizing and leading hunters over the past year. Teaming up with him, they investigate the case. During the investigation, more murders occur over seemingly small incidents, leading the Winchesters and Garth to discover that the murderers are possessed by a specter, similar to a ghost, but possessing people to get revenge for them rather than its own gain. The specter does this through people touching an old penny. Dean, angry with Garth for doing and saying things Bobby would say (such as using his catch-phrase "idjits" and wearing Bobby's hat) eventually lashes out at Garth. Meanwhile, in flashbacks viewers learn that Sam's former lover, Amelia, lost her husband Don, and the two begin a relationship. Eventually, the specter forces Dean to touch the penny, which leads Dean to want to kill Sam for not searching for him over the last year. Garth breaks the Winchester brothers up by taking the coin from Dean and burning the coin to destroy the specter. Because Garth is a naturally passive person with no wishes for revenge in life, the penny has no effect on him. The episode ends with Dean seeing Garth off, giving him back Bobby's old hat. Sam later tells Dean off about his grudge, warning him that if he can't let go of his anger, Sam will leave.
Source: Wikipedia
Source: Wikipedia
