ALIBI by Joseph Kanon

Joseph Kanon's Alibi exudes tension, especially on the part of its two main characters, Adam and Claudia. It's a case of seemingly good people doing bad things for good reasons, at least in their minds. Their actions, of course, compromise their goodness, and their consciences. Keeping a morbid secret between the two of them becomes an unbearable strain, on themselves and on their relationship. The story is set in Venice immediately after WWII, and Adam is a former investigator of German war crimes for the American Army. Claudia is an Italian Jew who stayed alive by becoming the mistress of a Nazi officer. Adam meets Claudia at a party while staying with his mother, who is about to marry an Italian doctor that she has known since before Adam's father died. Adam becomes obsessed with the notion that his mother's fiancé was a Nazi sympathizer, largely based on Claudia's eyewitness account of his having turned her father over to the SS. The plot becomes a bit tangled, and the finale is especially confusing. In any case, as far as the deeds of Adam and Claudia, the big question here is whether the end justifies the means.