'Supernatural' 101: How to Get Hooked

If you're not a Supernatural fanatic (yet), here are five pivotal episodes that will catch you up. Seasons 1-3 are on DVD, while 4 is on iTunes.

1. ''Home'' (Season 1)
Kripke wrote this exciting glimpse of the brothers' past in Lawrence, Kan., the mom (Samantha Smith) and dad (Jeffrey Dean Morgan) they lost, and how all four became involved with the supernatural.

2. ''Born Under A Bad Sign'' (S2)
Oooh, creepy: Sam is possessed by a demon, and in a long, frightening sequence, Dean tortures his brother/demon until he gives up supernatural info about — among other things — their father.

3. ''All Hell Breaks Loose, Pts 1 & 2'' (S2 finale)
Sam is stabbed and ''killed,'' hundreds of demons are let loose from hell, and Dean slays one of the show's best villains, the yellow-eyed Azazel (Fredric Lehne). These twinned episodes are models of how to wrap up a season: Give each star a few emotional moments, and spin the mythology forward.

4. ''Bad Day At Black Rock'' (S3)
In which we meet one of the series' more divisive villains: Bela, the bodacious, bombastic mercenary (Lauren Cohan). She and the boys tussle over a magic rabbit's foot, only to discover it brings bad luck to anyone holding it. The boys engage in lotsa atypical but hilarious sight gags.

5. ''Lazarus Rising'' (S4)
This episode reveals who brought Dean back from hell — the silky angel Castiel (Misha Collins), who seems an unstoppable force. He suggests that Dean has work to do for God, a vengeful God, one that would use Castiel as an emissary. And the demons just keep on comin'...