I am conflicted about this novel to be perfectly honest. Frei's depiction of life and experience in the days immediately after the end of the war between the Allies and Germany has the serious weight of authenticity and lived history. There's marvelous period detail, a powerful, evocative atmosphere of despair, shame, guilt, uncertainty, hunger, deprivation and post-traumatic stress on a national scale.
Unlike many serial killer stories the focus is more on the murderer's victims and their lives, used as a way to examine the Nazi years from a variety of perspectives drawn from all levels of society, some working better than others it must be said, with a tendency to cliché.
Tasked with solving the case of an accumulating series of murders of young blue-eyed blonde women, strangled and horribly abused, their bodies all found in the American zone in the district around Onkel Toms Hütte (housing estate, U-bahn station, shopping area) German Inspector Karl Dietrich, is an engaging character. He's a decorated war veteran who served with the elite Panzer division, struggling with the harsh conditions of life under Allied occupation and adjusting to life as an amputee. However, that focus on the victims mentioned above, leads to under-development of the police procedural, crime-solving aspect of the case.
More problematic is the nasty, lurid nature of descriptions of the serial killer's sexually motivated crimes, and passages of very bad sex in parts of the book detailing the lives of victims leading up to their murders.
The identity of this serial killer isn't hard to guess and the ending didn't quite convince me, but Frei's descriptions of the difficulties of life in postwar Berlin, a divided city under military occupation, held my attention throughout and kept me reading despite serious reservations about aspects of the book. Some readers of a more sensitive nature might be too disturbed, however. There is a lot of sexual violence, including descriptions of rape, as you would expect if you know anything about what happened to German women after Russian soldiers entered Berlin.
Woven, rather clumsily, into the book's narrative history of German experience during the 30s and through the summer of 1945 is a coming of age sub-plot involving Karl Dietrich's son Ben who deals on the black market instead of going to school, to buy a fancy outfit to making an impression on a girl he fancies. Ben's aspirations go unnoticed by his parents who are too busy with the demands of work and the daily struggle to survive. He is more realistic than other supporting characters who exist as types rather more than real people.
For further background I would recommend A Woman in Berlin, an anonymously published account of a journalist's experience of the final days under heavy Allied bombing raids and vengeance taken by the Russians on German women of all ages. Films such as Fritz Lang's M (pre-war) and Der Verlorene (1951) with Peter Lorre, and, of course, The Third Man portray the Noir atmosphere, tense with fear and betrayal, and for visual impact you cannot beat Roberto Rossellini's Germany Year Zero (1948), filmed in war-devastated Berlin.
The book's strengths make up for its flaws as far as I am concerned and I would recommend it, with reservations, to any reader with an interest in the German perspective on the immediate post-war experiences of ordinary Berliners. I would like to know what happens to the Dietrich family, so Frei must have done something right, to make me care for his characters.