This Time for Keeps (1942)

Dean questioning whether anything divine is real while Sam is literally dying is peak early‑season Supernatural chaos. It’s the first time the show rips the armour off Dean and forces him to confront something he can’t punch, fix, or bargain his way out of. That internal “is any of this real?” spiral becomes the backbone of his entire arc, and Faith is the moment it sparks. No wonder Heather picked it — it’s the episode where the boys stop being just hunters and start being two traumatised idiot