Two decades separate the abductions of five-year-olds Joanna and Matthew. For Matthew there is still hope, but time is running out. Detective chief inspector Karlsson discovers a link between the cases and calls on psychoanalyst Frieda Klein to interview Joanna's sister, who was close by when Joanna was taken. Meanwhile, Frieda's new patient Alan has been having dreams about taking a child who strongly resembles Matthew. A Ukrainian builder Josef adds a touch of humour, but is there more to him than meets the eye?
Blue Monday takes some time to get going as a series' worth of characters need to be introduced. However, once the pace picks up it becomes impossible to put down, with the twists coming thick and fast. Highly recommended.