The Last Temptation (novel)

Across northern Europe a sadistic serial killer has been gruesomely drowning experimental psychologists, and the case takes on a rare personal aspect for Tony Hill when one of his friends falls victim. Meanwhile Carol Jordan has gone undercover in Germany on the trail of some very dangerous crime kingpins. However Tony and Carol are caught together and the kingpin Tadeusz Radecki rapes Carol and tries to kill Tony. Afterwards Tony confronts Wilhelm Mann, the skipper of the barge Wilhelmina Rosen, who was killing psychologists because he was abused by his grandfather, who was experimented on by the Nazis. This culminates in Wilhelm being shot and killed.