"Closing Time" is the twelfth episode of the sixth series of Doctor Who. It stars Matt Smith as The Eleventh Doctor, Karen Gillam as Amy Pond, Arthur Darvill as Rory Williams, Alex Kingston as River Song, and James Corden as Craig Owens. Although Karen Gillam and Arthur Darvill are still billed (for what I assume are contractual reasons), they appear in only one scene. Alex Kingston appears in a closing scene that is a bridge to the next episode, that is not connected with the main plot of this episode.
Spoilers!
The Doctor has known for a while that he is fated to die on a beach in Utah, and the audience has known that even longer. Since the end of The God Complex, he has been spending time, some 200 years, racing across the universe on adventures. Right before he goes to find his destiny, he stops to say goodbye to Craig Owens, the companion he met briefly in The Lodger. But just as he is getting ready to leave, he picks up some weird readings and decides to stick around to fight one last alien invasion. He takes a job in a department store, working with James to track down a number of mysterious disappearances. Craig also has an infant son, Alfie, who makes the adventure more dangerous, more funny, and at the end, more successful.
After the twists and turns of the season, this episode is a bit of a respite. It is simple, uplifting, and has great comedic interplay between Matt Smith and James Corden. Of course, we shouldn't be too comfortable, because the next episode, things get really weird and timey-wimey again.