Dead Man's Blood

सीझन 1, एपिसोड 20: After a vampire hunter who was John's (recurring guest star Jeffrey Dean Morgan) mentor is murdered, Sam and Dean are surprised when John himself shows up to solve the case. When John discovers that vampires have stolen an antique gun that has the power to kill all supernatural beings, the Winchester family sets out to retrieve the weapon so they can destroy the demon that took Sam and Dean's mother.