Legendary Detective Ture Sventon has not solved a case in twenty years when his old arch enemy Vessla suddenly escapes from prison. Ture suspects that Vessla has a secret plan, linked to the mysterious Bermuda Triangle.

Ture sets off to Rimboanstalten to investigate Ville Vessla's disappearance. At the same time, Vessla wakes up on a ship together with a mysterious company in search of the forces hiding at the bottom of the Bermuda Triangle.