Lawyer Sven Adam is spectacularly shot dead on a nocturnal boat trip by the Marex company. His body disappears into the sea. Marex is a world leader in the mining of raw materials in the deep sea, specializing in rare earths. By mining these metals, which are found in every mobile phone, Marex wants to land a business worth millions. Did Adam's death have something to do with the killing of an environmentalist whoprotested against the destruction of the seabed? Sven Adam's wife Marte could also have killed her husband out of jealousy, because he had several affairs. Sarah Brandt discovers a video on Sven Adam's computer in which he openly accuses the Marex company of murdering him. Inspector Borowski suspects that the solution to the case can be found at the bottom of the Baltic Sea and dives into the depths.