Supernatural: The Anime Series

Reunion (1x14)

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A series of bizarre murders occur in Colorado and a hunter named Daniel Elkins is among those killed. Sam and Dean think that it was done by a vampire and head out. Once there, much to their surprise, they find their father, John. Needless to say, the brothers are very happy and, following John's instructions, they set out to find the Colt, a gun stolen by the vampire that killed Elkins. Though Sam can't help but complain about the fact that John won't explain anything to them.