I Know What You Need

"I Know What You Need" is a fantasy/horror short story by American writer Stephen King, first published in the September 1976 issue of Cosmopolitan, and later collected in King's 1978 collection Night Shift.

Plot summary
Elizabeth Rogan, a popular college student, meets social outcast, Ed Hamner, when she is cramming for a sociology final. Ed offers to buy Elizabeth a strawberry ice cream cone, which was on her mind, and offers her the answer key to the final, claiming he had already completed the class. She gets an A on the final, saving her scholarship, but informs Ed that she has a boyfriend named Tony.

What Elizabeth anticipated to be a great summer turns out to be anything but, as tips at her job at a seaside resort are sparse due to a combination of lousy weather and high gas prices. Even worse, Tony is pressuring her to drop out of school and get married, claiming his construction job can provide for them both. Tony dies one week later when he is struck by a Fiat while performing road work. Ed reappears at this time and the two begin dating, with Ed seeming to be the perfect boyfriend.

Elizabeth's roommate repeatedly warns her that Ed is being manipulative by setting up circumstances to make himself seem perfect. The roommate's father hires a detective agency to do a background check on Ed, where it was revealed that he had attended the same elementary school as Elizabeth but moved away when his father, a compulsive gambler, fled mob-connected debt collectors. Ed's father used his gift to reverse his fortunes at gambling, and later invest in the stock market. Ed's mother, a religious woman, had been committed due to her rambling claims of having given birth to the devil.

The background check also shows that Ed was never enrolled in courses at Elizabeth's college, and thus could not have attended the sociology course the previous term. The roommate also reveals that Ed's father died in an accident along with his wife in a manner similar to Tony's death; they had been out picknicking when their car careened over a cliff. As Ed was the sole surviving member of the family, he inherited his father's stock portfolio of well over $1 million.

Elizabeth locates a diary Ed has kept, documenting how he has secretly craved her love since childhood and employed a variety of black magic rituals and charms to manipulate her and murder Tony. She finds how his residence is akin to a Potemkin village, where his bedroom is a mess, reflecting his unkempt personal appearance, whereas the front is well kept, likely to impress Elizabeth and other guests. She finds voodoo dolls of his parents, as well as herself. Other items she finds are an answer key with "BETH" written in grease pencil on it, and a toy model of a Fiat.

Ed confronts Elizabeth and calls her an "ungrateful bitch", to which she accuses Ed of killing Tony. Ed fully admits to using his powers to eliminate Tony, defending himself by saying he did it for her; to save her from an unhappy marriage. Elizabeth destroys her voodoo doll and leaves the house with Ed's magical artifacts. While walking she passes on a bridge and throws Ed's voodoo dolls over the rail, throwing the toy model of the Fiat last.

References to other works

 * One of the books Ed has is the Necronomicon from the Cthulhu Mythos.
 * The setting of the story is 1973 to 1974, as the 1973 oil crisis and The Godfather are mentioned.

Film versions
Shawn S. Lealos directed a short Dollar Baby film based on this story under Starving Dogs Productions.

Another short Dollar Baby film version of the story was filmed in July 2021 through crowdfunding and is directed and produced by Julia Marchese, who cites the story as her favorite among King's works. A teaser trailer was released on August 30, 2022. The film premiered at the 2023 Maine International Film Festival.