I'll try to post these every other week day (Mon-Wed-Fri), but I make no guarantees. Sometimes there will be more than one cap for a beginning or ending of an episode. I'm also using my capper's discretion - meaning I'm choosing the most aesthetically pleasing image that we see first or last not always literally the first or last things we see. I'll explain this as we go along.
:: Click on images for the HQ versions ::
4.02 Beginning: An unknown hunter who is about to meet a bloody end in the episode's teaser.
Our first view of the boys is of them arguing about the existence of angels while in Bobby's kitchen.
4.02 Ending: The episode ends with Dean having a little talk with Castiel while dreaming, learning of Lilith's plan to break the 66 seals to free Lucifer. Dean wakes up in the morning and asks Sam if he believes in the devil.