The upward swing of the seventh season of Supernatural continues with the not at all spoilery return of Castiel (Mischa Collins), Sam's steep slide into insanity thanks to Lucifer (Mark Pelligrino), and strong character work all-around. Besides the premiere, it's the first essential episode from this season.
More spoilers and impressions after the jump.
Remember how last week Sam was dealing with an extra-frisky Lucifer in his head after inadvertently letting his imaginary Satan in while investigating a string of demonic murders? Well, apparently Sam hasn't been sleeping well (or at all), and it's slowly, inexorably driving him insane. At the top of the episode, the youngest Winchester makes a drug buy, gets hit by a car, and ends up institutionalized (and reading that back now, it seems like the denouement of the world's saddest after school special). At every turn, Lucifer is there screaming in Sam's ear, putting visions in his head, and generally being obnoxious, and it turns out a steady stream of 24-7 pranks can put you out of your own head.
So Dean hits Bobby's Rolodex to find someone who might be able to help Sam, leading him to a mysterious healer calling himself Emmanuel. And who does he find but good old, Castiel, his memory completely erased, with no knowledge of demons, angels, or his own actions that led to the release of Leviathan on Earth. What follows is an awkward road trip as Dean tries to avoid reminding Cass of things maybe best left forgotten. Then the road trip gets dangerous as demons get on their trail in the attempts to get hold of Cass. Then the road trip gets even more awkward as sometimes ally Meg the demon (Rachel Miner) shows up offering muscle (and a constant stream of hints directed at Castiel to remind him of who he is).
While Meg's plan to try to somehow gain Cass as an ally seems half-baked, the rest of this episode serves as a nice redemption arc for the boys' angelic BFF. He went out at the beginning of the season sacrificing himself to stop the creatures from Limbo from invading the Earth, but he also went out messy and bad. Collins does fine work showings a bunch of emotions and character traits at play in the normally taciturn angel, from simple innocence and gentleness as Emmanuel, to pain and anger at himself when he remembers all of the lives he's taken in the last year. The writers also find a clean (albeit not necessarily entirely well thought-out) solution to Sam's deteriorating mental state by allowing Castiel to pass Sam's madness into himself. The one problem I see with that: now you have crazy, super powerful angel.
One other small touch you might have missed: when Dean was looking for names among Bobby's papers, it looks like the late, great Mr. Singer (Jim Beaver) might have provided a little invisible nudge in one of a couple of nods to Bobby possibly sticking around to provide support from beyond. It's another terrific little detail that makes this one of the strongest episodes of the season and really gets to the heart and the sentiment of the characters.