10 Greatest Star Trek Cave Episodes
2. The Devil In The Dark
Hell is empty, and all the Horta are here. Or so it seems when the Enterprise responds to a distress call from the mining facility on Janus VI. The humans there are being attacked and killed in a rather horrific fashion by a terrifying tunnelling silicon-based lifeform. This is a nearly 60-year-old spoiler by now, but the Horta is suffering too. "Paaain" is the theme of this descent down to the seventh level of the Star Trek caverns. Hell is not the Horta; it's other people.
The Devil in the Dark is a favourite amongst fans, typically ranking highly on any 'greatest' lists and often cited by actors, writers, and producers as a particularly noteworthy instalment. One might be tempted to ascribe its success to the cave/mine location, but it's a set of strong performances and the plot's central thesis — if you immediately cry 'monster,' you might want to dig a little deeper — that make the episode stand out. Nevertheless, the tense atmosphere afforded by the enclosed space of the cave does help!
The Devil in the Dark also treated us to the joyous "I'm a doctor, not a…" ("bricklayer," in this case) for the first time. Indeed, it's McCoy's masonry that saves the injured Horta, along with a memorable mind-meld from Spock.