A body is found in the water near Liljeholmen. The body belongs to a 39-year-old Danish citizen with a solid criminal record and who was a member of a notorious Danish drug gang. Should the Beck Group get a gang war on their necks? Martin Beck is back to the joy of the entire Beck group. Martin's daughter Inger is not as happy but has to accept her father's decision to start working again.

A small group of friends are gathered at Katinka's summer house to celebrate her birthday. The guests are all in their thirties, upper class, art world, liberal humanitarian bohemians. They sit on the floor smoking amongst books, antiques and modern art. The party sets off on a high note, when suddenly during dinner, two new guests arrive. Linda, a blonde game show hostess, is unexpectedly brought to the party by Katinka's brother. Linda is greeted warmly at first, her brusque and liberated manners are entertaining and fresh. But during the course of the evening Linda stretches the groups invisible social rules of hospitality. Contempt starts to grow, thus unfolding the groups hidden prejudices.