Reykjavik police investigator Huldar has never encountered such a case before. A young woman is brutally murdered in her home. The killer's handwriting is creepy and bizarre - nothing like this has ever happened not only in Iceland, but also in other countries. The criminal did not leave any evidence - except for a note with a strange digital cipher, which the best cryptologists have already broken their teeth on. The only witness is the little daughter of the murdered woman, quietly huddled under her mother’s bed. But she is shocked and does not answer questions. Freya, a specialist in working with traumatized children, works together with Huldar. With her help, only the following can be extracted from the girl. The killer is all black. He has a big shiny head. And he's going to kill another woman...