Two 16-year-olds, Félix and Elisa. They meet playing the Blue Whale Game, fall in love and decide to take on together the game's final challenge: Suicide.。In their last attempt to save their marriage, Sara and Óscar decide to take a short vacation in a cabin in the woods with their two children. But upon arrival, strange events corrode the tense atmosphere between them: a woman prowls the house predicting events that defy nature, which break the family from within as they confront unresolved problems from their past.。