A quietly effective crime story that delivers a considerable punch. Icelandic police detective Erlendur is approached by the friend of a suicide victim who has doubts about the death and he agrees to investigate it further. At the same time a thirty year old missing person case is weighing heavily on his mind. As he steadily pursues his investigations into both cases it becomes clear that there are significant questions regarding both that need to be answered. The reveals are quiet and superbly staged, the apparently irrelevant investigations into the two cases starts to reveal unexpected turns. The conclusion is as cold and gripping as the hypothermia of the title. Arnaldur Indridason has taken an interesting route in this book, the investigations are shrouded in questions of memory and loss and how they can overshadow the the present. Erlendur is conducting the investigations as a private crusade, there is no official reason for them and the question of why he is undertaking them is nicely woven into the story. The Icelandic context is strongly drawn in the story and adds to the flavour of the book. The structure of the narrative is clever, the suicide victim emerges as someone looking for answers all her life and seeking them in increasingly strange places. the way her search to understand her past collides with the present is subtly and effectively woven together. The missing person case stirs a dark pool of memory and long term loss with skill and a melancholy grip. Thoughtful and gripping, a great read.