A man is found dead, stabbed to death with a knife. The shocking thing is that his face has been removed. After questioning his wife who described the marriage as happy also told that a mysterious foreign man knocked on their door the day before the murder. Beck and his men are given the case.

A series of grisly murders where the victims faces have been removed by acid starts to turn up around Stockholm. Detective Martin Beck and Gunvald Larsson are once again drawn into the darkness.