It's been five years since tragedy struck and Martin lost his wife and son. Five years since they vanished without a trace while they were on a cruise ship. Ever since, the police psychologist has been a wreck. Tortured by the thought of his wife having committed a murder-suicide. Suddenly, there seems to be a new lead. A strange woman calls and claims she has proof her family was actually murdered back then; even claims that it's happening again. She urges him to come on board the very cruise ship on which his family disappeared. Another mother and her child have gone missing. But this time, the girl turned up, alive but traumatized – holding a teddy bear that used to belong to Martin's son. It seems to be the work of a serial killer… but why are they targeting only mothers and their children?