The Little Sisters of Eluria. This short story that is a companion to The Dark Tower mythos is found in Stephen King’s Everything’s Eventual. The story has since been adapted into a graphic novelization by Marvel Comics Group and also been re-released as a novella.
The story is set just before the start of The Dark Tower I: The Gunslinger. Roland has been following the man in black Walter O’Dim across the desert. He arrives in the ghost town of Eluria which seems abandoned except for a stray dog with a peculiar crucifix shaped marking on its chest; and the body of a dead man the dog is trying to feast on. After he chases the dog away from its prize, Roland spots and takes a medallion from the corpse. Just then, he is attacked and knocked unconscious by a gang of slow mutants.
When he awakens, he finds himself suspended in the air by bandages and that he is inside a tent that is
serving as some form of infirmary. He is greeted by nuns that call themselves “The Little Sisters” and they claim to be nursing him back to health. Little bugs called “doctors” come in each night and “repair” Roland’s wounds. He notices another patient in the cot next to him, who is also suspended in bandages. That man turns out to be the brother of the corpse in Eluria.
Roland begins to suspect that all is not right with “the Sisters” from their nightly visits to the infirmary. Also, he begins to realize he is being drugged to weaken him and the medallion that he took from the corpse seems to have a repelling affect on them. One night, Roland awakens to find the Sisters bring in a Slow Mutant and has him take the medallion off of Roland’s room mate. The Mutant realizes he will be killed after he removes the medallion, he slashes the man’s neck and the Sisters ravenously feed on the dying mans blood while the mutant makes his escape.
Roland befriends the youngest member of the Sisterhood, Jenna. She wants to get out of the coven of vampiresses and so she helps him escape using her power over the “doctors.” The two fall in love, but it is short lived as when the sun rises the next day, she disintegrates into a swarm of Doctor Bugs.