Investigator Karsten von Hoesslin travels the world to learn who killed four men at sea. His first clue is mobile footage that captured the crimes.

The investigation takes off. In the Philippines, Karsten hunts for witnesses and explores the brutal world of illegal fishing and human trafficking.

Karsten interviews witnesses to learn more about the murders. Looking for a motive, he goes to the Seychelles and encounters illegal fishing.

Could the motive behind the killings involve drug trafficking? Karsten investigates the murky underworld of Mombasa and makes a major breakthrough.

No bodies, fingerprints, or DNA. Will Karsten be able to identify the victims in the video? His quest takes him deep into Somali pirate territory.