"There is a curse on your ship. Leave this place, or you will all die."
These words come from the mouth of a dead crewman named Jackson (Jay D. Jones), the only member of a three man landing party that has been able (or allowed) to return to the Enterprise. With two crewmen, misters Scott and Sulu, still missing, Kirk, Spock, and McCoy beam down to the supposed lifeless planet to find and rescue them.
What they find is a bizarre, gothic style landscape. One that seems to have been lifted out of the stories of Edgar Allan Poe (or H.P. Lovecraft).
After facing spectral witches, thick fog, a howling and powerful wind, an ominous castle, and a black cat, an irritated Captain Kirk comments to Spock and McCoy, "I'd say someone was playing an elaborate trick or treat on us."
And he is correct. Someone is playing an elaborate Halloween themed prank on the crew of the U.S.S. Enterprise. That someone is screenwriter Robert Bloch, and he has a grand old time doing it.
With Catspaw Bloch pulls out as many stops on Horror story tropes as the episode's running time and production budget will allow. Granted these are 1967 Horror story tropes. That means lots of set obscuring fog and mist draped over the kind of Gothic Horror imagery that, with the period horror films of Hammer Studios and Roger Corman's Edgar Allan Poe pictures playing at local theaters and drive-ins, contemporary viewers were sure to find familiar enough to think, "Wow, Kirk and the crew have gone and beamed themselves into an honest-to-goodness horror movie!"
While cackling witches, a black cat that can change its size, and a castle that sports a dungeon with skeletons hanging from its walls (which Bloch then uses as a set up for a terrific running gag) remain recognizable horror tropes for 21st century viewers. They are antiquated ones. In this day and age, the castle would become a decrepit old house. One with an adjacent cemetery, preferably, that is plagued by zombies. The witches would be replaced by a strange (and deranged appearing) drifter, not at all unlike Friday the 13th's Crazy Ralph, or the hitchhiker from The Texas Chainsaw Massacre.
You know, a harbinger of doom that would be a bit more recognizable for this generation.
Of course, that will all change with the next generation, and the whole thing will become more of a self-aware joke.
The connection between Catspaw and The Cabin in the Woods is a pretty strong one. Both feature persons being used by others as dupes or tools (which is the very definition of the word catspaw). Both take place inside a simulacrum of a "real" environment based upon the nightmare images culled from the collective subconscious of the contemporary culture. Both make reference to Old Ones. Both explain away magic and supernatural events as nothing more than science created hocus-pocus. Smoke and mirrors that are meant to obscure what is really going on.
How the characters in the simulacrum become aware of their entrapment and fight back against their captors is where the narrative paths of the two stories diverge. The path Catspaw takes is identical to the one taken in the second episode of season two, Who Mourns for Adonais? The characters confront an antiquated (albeit seemingly omnipotent) supernatural power they know cannot exist in reality. They struggle to find out how and why they are being used. They discover the source of the omnipotent appearing being's supposed power, slash its Achilles' Heel, cripple it, defeat it, and then banish it. On to the next episode's adventure.
Because I am a huge Horror genre buff, and an even bigger fan of Robert Bloch, I prefer Catspaw over Adonais, because it plays in my preferred ball park. Bloch brings his trademark wit to the episode, so there is a playful tongue-in-cheek feel to the proceedings. One that helps gloss over the muddled, to say the least, explanation of whatever it was that Sylvia (Antoinette Bower) and Korob (Theodore Marcuse) had been sent by the "Old Ones" to do. Were they advance scouts of an alien race, sent to study humans, prior to engaging in a first contact? That's kind of what it sounded like... I think. It was all rather confusing, really. Confusing to the point of being nonsensical, actually.
Nonsensical because, at its gooey and candy filled center, Catspaw cannot hide the fact that it is nothing more than a gimmick. It's the original series one and only Halloween themed episode, with the crew of the U.S.S. Enterprise taking a trip through a Haunted Castle. The unique novelty of its concept is what helps make Catspaw memorable, nothing else.