Who in the Pool(2015)

Who in the Pool is a horror film set at a day spa resort where an engagement party takes a sinister turn. When the ghost of a long-dead friend returns seeking revenge, the celebration descends into chaos and terror. The guests must confront both the supernatural threat and the dark secrets from their past that may have triggered the haunting. As the body count rises, they realize the vengeful spirit won't rest until its thirst for retribution is satisfied. The film blends slasher elements with supernatural dread, trapping the characters in an isolated setting where escape seems impossible and trust becomes a luxury they can't afford.