This article originally appeared on Den of Geek UK.

Over an extended run, some television shows give off the impression that all life in their universe revolves around a small number of characters, but if they run long enough, writers and producers will invariably have to look elsewhere every once in a whle. Maybe on another day to every other episode, when the forces of evil rally and all seems lost, the good guys are… otherwise occupied, leaving someone else to pick up the slack.

As a dramatic convention in pop culture, foregrounding minor characters dates at least as far back as Tom Stoppard’s 1966 play Rosencrantz & Guildenstern Are Dead, which takes place “in the wings” of Shakespeare’s Hamlet as the two minor characters have little comprehension of the tragic events going on concurrently. But over the years, geek TV has given us quite a few good examples of the same.

In a production context, the rigors of a long season can sometimes make these kind of episodes necessary in order to give the regular cast a break, but they almost always help to flesh out a TV show’s pocket universe and make it feel more lived-in. This reason mostly applies to the US model, which is why the following look at some of the notable episodes of this kind includes only one British TV show, and it’s just about the only one to which these circumstances could possibly apply.