The Cliff (2016)

Gabriel is a Assistant District Attorney from Bilbao, Basque Country (north to Spain) whose happy life with his work and his wife Patricia shakes after to receive a calling where he is noticed that his younger sister, Cordelia, has died after a mass suicide of a sect who lived in the island of Las Palmas de Gran Canaria, who jump of a cliff to crash against the sea. Moving to the island, Gabriel meets Helena, Cordelia's friend and former housemate, because the two are required to identify the only one corpse not identified clearly. Realizing that Cordelia isn't the corpse they see, Gabriel moves to Helena's house in order to wait news from Inspector Santana, a woman very implicated in the investigation after the disappearance of a cop who she secretly infiltrated in the sect to find evidences of illegal activities. But tired of the waiting, Gabriel and Helena decide investigate by their own risk the sect and their members, trying to discover what caused the suicide and if Cordelia could be still alive...