Doctor Who: Steven Moffat's Timey-Wimiest Episodes

This single-episode masterpiece which coined the term “timey-wimey” in the first place is a densely plotted story which uses many ideas about temporal mechanics to cram a lot into its short runtime.

Blink introduces the Weeping Angels, lonely creatures who cannot move when being observed, but are impossibly fast when unseen. These creatures kill by sending their victims back in time to live out their lives in history, giving the Angels temporal energy to feed on. This happens to twice in the episode, giving us an overview of two entire lives, told as quick side stories.

And this is just one part of the elegant jigsaw puzzle of overlapping time loops that Blink offers, with guest protagonist Sally Sparrow (Carey Mulligan) discovering elaborate communications left to herself by the Doctor. Messages are written beneath wallpaper, hidden on DVD’s, and entrusted to people to arrive at preset times. Most impressively, Sally has a full-fledged real-time conversation with a pre-recorded video of the Doctor that is decades old.

In the end, Sally discovers that the Doctor’s ability to “talk” to her has come from elaborate notes that she herself delivers to him—before it happens from his point of view, but long after from hers--making the whole episode one giant delightful closed time-loop of a story.