The Dark and Deadly Pool

For fans of Gillian Flynn, Caroline Cooney, and R.L. Stine comes The Dark and Deadly Pool from four-time Edgar Allen Poe Young Adult Mystery Award winner Joan Lowery Nixon.
 
        Liz enjoys her summer pool job at the glamorous Ridley Hotel. Until the dark and lonely night when a ghastly shadow surges up from the pool. A face—eyes wide, mouth gaping—stares at Liz. A hand clutches at her sneaker. Then it, whatever it is, is gone.
        But danger isn't. Strange things are happening at the hotel, and a shaken Liz wants to know why. But whoever is behind the trouble will stop at nothing—not even murder—to get what he wants.
 
"[A] suspenseful mystery, rounded out with touches of humor and romance." –Publishers Weekly