Fantasy and horror have basically been outlawed on Earth. About 30 years ago, there was a big book burning and Stendahl is still pretty cheesed about what happened to his library.
(Hint: it got burned.)
Unfortunately, the same people who banned fantasy on Earth have now come to Mars.
The Investigator of Moral Climates, Mr. Garrett, comes to investigate this house's, you know, moral climate.
Apparently the Moral Climate isn't up to snuff, because Mr. Garrett wants the house torn down.
But before Garrett can do anything, one of Stendahl's robot apes kills him. (Yay?)
Luckily, Stendahl is working with a man named Pikes, who was a great actor, makeup artist, special effects artist, or something like that in Hollywood.
Just as Stendahl is angry about his library being burned, Pikes is angry about his films being destroyed.
Pikes makes a robot version of Garrett so the two masterminds can continue on their merry way without being investigated for, you know, murder.
This is their plan: Stendahl has invited many important book burners to his house, including the top members of the Society for the Prevention of Fantasy. He gets them to wear costumes—which, for some reason, they'll do just this once, even though they're generally against costumes.
People will do anything for a good party.
One by one, the book burners die in suspiciously literary ways. (See "Shout Outs.")
Or do they?
Stendahl tells the rest of the guests not to worry, because the ones who are "dying" are just robot lookalikes.
Meanwhile, Pikes discovers that the Garrett they killed was actually just a robot. Real Garrett shows up to the party, without bringing any refreshments or presents.
He's ready to start with the house-tearing-down, but first Stendahl and Garrett watch the other robots get killed in strange ways.
Finally, Stendahl takes Garrett down to the cellar and walls him up.
Now it's time for the big reveal: Stendahl confesses that everyone who died was actually the real person, and the robot lookalikes were the ones watching.
Stendahl destroys the House of Usher and flies away with Pikes to live happily ever after (a phrase that the Society for the Prevention of Fantasy wants to ban).