Screen Gems prevailed in a spec auction for “Beautiful Girl,” a scary genre thriller from a most unlikely source: Michael Cunningham, the Pulitzer Prize-winning author of “The Hours.”

Douglas Wick and Lucy Fisher are producing through their Red Wagon banner.

Story concerns a shy but brainy high school girl who returns for senior year after having slimmed down six dress sizes. She finds herself flirting with the handsome English lit teacher, but the mutual crush turns deadly when the teacher’s obsession with the student compels him to exact maniacal revenge on everyone who was cruel to her.

Screen Gems president Clint Culpepper met Cunningham through Wick and was surprised to find a genre junkie, even if his love of blood-soaked movies didn’t seep into his books, or scripts like “A Home at the End of the World.”

Cunningham said he has always been a huge genre fan and, when sitting with Wick, would argue such basics as whether the second “Hostel” was as good as the first one.

“While I was writing about Virginia Wolff, my mind was never far removed from the idea of girls in bikinis being hacked up by guys wearing hockey masks, and I vowed that if I ever had a good idea, I would write one of these scary movies,” Cunningham told Daily Variety.

“We’ve become such genre paisans, and when I showed the script to Doug, he showed it to Clint, and it was instant love,” Cunningham said. “This summer, I will finish a novel where nobody gets anything gouged out of them, but my plan is to then write another idea I have for an actual monster movie. As it turns out, we sometimes find we can do more than one thing in our lives.”

Cunningham is repped by CAA and lit agency Brandt & Hochman.