Children swimming instructor Sven Haasberger gets beaten up in broad daylight. Someone accuses him to be a pedophile. But every evidence against Haasberger turns out as faked while he dies in hospital.
On a boat trip the company lawyer of Marex is shot. His body disappears into the sea. Borowski suspects that the resolution of the case can be found in the depths of the Baltic Sea. Marex is a deep-sea mining company.