After investigating the death of a lawyer (guest star David Quinlan) who appeared to have been killed by a wild animal, Sam (Jared Padalecki) and Dean (Jensen Ackles) realize they are tracking a werewolf.

Sam is immediately attracted to the lawyer's secretary Madison (guest star Emmanuelle Vaugier) and when it seems as if Madison will be the werewolf's next victim, Sam offers to stay overnight to protect her. Dean heads out to hunt the animal and is stunned by what he finds.