Blue Monday by Nicci French

London psychotherapist Frieda Klein agrees to take on patient Alan Dekker from her mentor Reuben McGill, whose personal problems are affecting his work. Alan hasn't been feeling like himself and he's having a recurring dream about a fictitious son--around five years old with red hair. When a boy named Matthew Faraday who matches that description goes missing, Frieda wonders if she should contact the police. Frieda does end up speaking to DCI Malcolm Karlsson about her concerns. When he hears all she has to say, he feels that the police need to look closely at Alan. Karlsson, himself, has discovered a connection between Matthew's disappearance and that of Joanna Vine, who went missing over twenty years ago. What follows is a nail biting ride, following Frieda and Karlsson as they attempt to find both Matthew and Joanna. With this first book in a new series, French has created an interesting main character in Frieda and a story with lots of twists and turns. A hard one not to devour in one sitting...