The narrator and his uncle, Dr. Elihu Whipple, investigate an old house with a disturbing reputation for either driving its occupants insane or causing them a slow wasting death.
This story contains examples of:
- Bittersweet Ending: The protagonist's uncle is killed, but they succeed in destroying the entity beneath the house, and the curse over the house disappears.
- Buried Alive: Implied to be how the lynching victim in the flashback parts became a vampire. The townsfolk interred him in the basement of his own house.
- Crazy-Prepared: The protagonist suspects that he has discovered a vampire, but knows better than to rely on a wooden stake and hammer, instead bringing a pair of flamethrowers and a Crookes tube, "in case it proved intangible and opposable only by vigorously destructive ether radiations". This being a Lovecraft story, it turns out neither of these are appropriate weapons for what's actually going on.
- The Cloud Cuckoolander Was Right: Ann White was a hired maid who was convinced that the phenom behind the wasting sickness and madness that afflicted so many people who lived in the house was the work of a vampire, and they needed to exhume the cellar to look for it. She was fired for being superstitious. And a century and a half later, it turned out she was completely right about everything.
- Demonic Possession: This is how the monster works. Its presence also drains the life out of the victim, in addition to driving him to Ax-Crazy physical vampirism.
- Did You Just Punch Out Cthulhu?: The monster is a high-powered and particularly grotesque type of vampire; attacking it with guns, flamethrowers and directed energy weapons fails. Its spirit form is effectively invulnerable, but its buried body, which functions as its Soul Jar, can be destroyed with physical means, and it is eventually killed by pouring sulfuric acid over it.
- Dying as Yourself: Elihu Whipple transforms into a rotting monster under the house's influence. It then takes the forms, in rapid succession, of all those who had lived and died in the house. As the monster is on the verge of disintegrating completely, it takes on, after an apparent struggle with itself, the kindly appearance of Whipple once again. "I like to think," says the protagonist, "that he existed at that moment, and that he tried to bid me farewell."
- Evil Smells Bad: The house is noted as positively reeking of decay and foulness. After the monster is vanquished, the smell disappears.
- Gas Leak Cover-Up: "All along the hill people tell of the yellow day, when virulent and horrible fumes arose from the factory waste dumped in the Providence River, but I know how mistaken they are as to the source. They tell, too, of the hideous roar which at the same time came from some disordered water-pipe or gas main undergroundbut again I could correct them if I dared."
- Haunted House: The hero of the story becomes obsessed with a mysterious house that, since it was first built, wound up either driving its occupants insane or causing them a slow wasting death. It turns out that the house was built over the final resting place of a magician who slowly drained the Life Force from the people near him in the night.
- Hollywood Acid: The climax of the story has the protagonist dig up the monster's body and pour six carboys (large vats) of sulphuric acid into the pit, killing it. Sulphuric acid is actually pretty slow acting, but it kills the monster instantly. Of course, the exotic substance of the body might also play some part in this.
- Inspired by...: The house actually exists, as did Jacques Roulet, the psychotic French 'lycanthrope' from the short story. Of course, the two never really had anything to do with each other, and H.P. Lovecraft only chose to write about the house because it was pretty creepy looking.
- Lovecraft Lite: This story is essentially the less horrifying and more upbeat companion to The Colour Out of Space. The basic plots are very similar, but the monster of "The Shunned House" is (relatively) more human than the completely alien horror of the latter story, and can ultimately be defeated through human effort and sacrifice.
- Madwoman in the Attic: Rhoby Harris. After the presence haunting the house attacks her, her protests are dismissed as just another symptom of her insanity.
- Old, Dark House: Downplayed in that looking from the outside it doesn't seem particularly ominous or special.
- Our Vampires Are Different: The vampire manifests itself as a cloud of yellowish, man-eating fog. It's a vampire with no physical manifestation, who drains its victims of their life force. Its attacks are restricted to residents of the house in which it once lived.
- Shapeshifter Swan Song: As the monster dies, it displays the faces of its victims, ending with the narrator's beloved uncle, who had tried to help him destroy it.
- That's No Moon!: A variation. The protagonist digs under the house and finds a strange, two-foot-thick folded translucent tube. Which, once he gets past his confusion from the scale and seeing it independent of the rest of the owner's anatomy, he realizes is an elbow.