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 ::
4.20 Beginning: This episode opens with Dean relaxing by the water and fishing, but we quickly discover it's just a dream so Castiel can talk to him.
4.20 Ending: By episode's end Cas is back in Jimmy's vessel, Dean has found out about Sam's demon blood drinking, and then they drive to Bobby's place where they lock Sam up inside the panic room.