Darkly by Marisha Pessl

Dia Gannon, along with six other teenagers, is chosen for a competitive internship at Darkly, a game company founded by the mysterious Louisiana Veda. But it isn’t a typical internship, as the company closed its doors after the death of its eccentric founder decades ago, causing its games to become collectors’ items worth millions. Upon arrival in England, the interns are asked to solve a crime by playing—and winning—Veda’s final game. Dia is a quirky and endearing main character thrust into the core of Veda’s shuttered operation with kids she doesn’t trust, navigating her way through one of the most immersive, eerie puzzle games ever created. Pessl’s novel is part-mystery and part-horror, but is a fully addictive read as Dia and the other interns unfold Veda’s backstory as they solve the mystery of her last game. The rapid plot twists, vivid game details, and brooding atmosphere create an unforgettable read.