...the Winchesters arrive! Dean shouts for Castiel, but Reapril sends Sam and Dean flying around the room. Sam gets thrown into a closet, and while Reapril takes a break to make a quip, Dean stabs her with an angel blade of his own. They're so multi-purpose! Reapril is dead... ...but so is Castiel. Dean is devastated, but Ezekiel takes over for Sam and puts his hands on Castiel, healing and resurrecting him. Dean looks as though he doesn't know how to feel; after all, Cas is alive, but Ezekiel is getting a little bit to proactive in overpowering Sammy's consciousness. "Never do that again!" Dean shouts at Castiel. "Alright," consents Cas apologetically. Aw. Unfortunately for Dean, however, Cas and Sam then begin to question how Cas was suddenly not dead. As if either of them have room to talk! Dean lies successfully, and he looks indecently pleased with himself for having gotten away with it. Bunker. Castiel likes the bunker, what with all of the water pressure and burritos and Dean. He mentions his romp in the sheets with Reapril, and they all start giggling and making jokes about "protection." Whatever. Cas goes off in search of more burritos, leaving Sam and Dean to presumably laugh some more about Cas roundin' the bases. Before they can start high-fiving, Ezekiel takes over again and gives Dean an ultimatum: either Cas leaves, or he does. As Ezekiel's departure would mean Sam's death...we all know where this is heading.
But that doesn't make it any less heartbreaking. Dean approaches Castiel to deliver the bad news, asking if they can talk. "Of course. Dean, you know I always appreciate our talks, and our time together," says Cas. It's so sad. Dean has to force himself to look Cas in the eye. "You can't stay," says Dean, and--because he has a much stronger will than I do--he does not immediately melt at at heartbroken expression on Castiel's face and tell him that he was kidding and that Cas can stay forever.