In "Salvation," Sam and Dean finally reunite with their father, John Winchester. The trio is on a mission to stop the Yellow-Eyed Demon before it strikes another family.

Supernatural Season 1, Episode 21, "Salvation," is a high-stakes turning point in the series. As the Winchester family edges closer to the demon that killed Mary, the tension reaches a breaking point. Episode Recap: The Hunt Intensifies

The Winchesters have the Colt, the only gun capable of killing the demon.