Department "Q" of the Copenhagen police took up a very unusual case. From Scotland, a small bottle washed up on a deserted shore was sent to Danish detectives. She kept a message written, as local police were able to establish, in Danish. The fact that instead of ink, human blood was undoubtedly used was of keen interest to law enforcement agencies of both countries. Little remains of the text—time and sea water have taken their toll—so Commissioner Karl Mörck and his assistants began deciphering it. And gradually a terrible story began to unfold before their eyes about abducted children, years later crying out for help...