Star Trek: The Original Series, Series 2, Episode 13. First broadcast on Friday 15 December 1967.

A few tense moments this week, as a fragrant dikironium vampire kills a bunch of redshirts before threatening some characters with names and ultimately the Enterprise itself. But the real suspense comes from an entirely different direction: Will this episode teeter over the edge of camp into baffling semicompetence? Will Kirk’s obsession turn him from a jovial and beloved authority figure into a massive idiot? Will any cue from the Star Trek music library go unused? (No, no and no, fortunately.)