Supernatural (TV series)/Recap/S04/E03 In the Beginning

Season 4, Episode 3:

In The Beginning
Castiel sends Dean back in time to discover a bit of history: how Sam came to be chosen by Yellow-Eyes, and how his parents got together.

Tropes

 * Fish Out of Temporal Water
 * Shout Out: when the guy goes back in time, ends up in a diner, hears his name called, and turns to find the guy he's been sitting next to the whole time is his dad. Dean even lampshades it when he confronts Castiel.
 * Squick: Just like the Crossroads demon, Azazel seals a deal with a kiss... while he's possessing the father of the person he's making the deal with.
 * Time Travel