When another dead elderly gentleman is fished out of the Thames, Inspector David Perkins is convinced that the gorilla gang is active again. On a doll found with the body, characters of an African language are discovered. Together with Sergeant Pepper and language specialist Susan MacPherson, the search for the head of the gang begins.

After a long absence, forest ranger Hans Freese returns to the heathland village of Undeloh, where he spent his childhood. Here he meets his childhood sweetheart Rose again. A sophisticated publisher from Hamburg and a group of gypsies cause all sorts of complications, but thanks to these, Hans and Rose are finally able to be together.

Murder mystery about the disappearance of a boy who has leukaemia following the murder of his mother, which he witnessed.