Showing Alibi by Joseph Kanon

Adam Miller had had a long war, and when the US Army let him go he made his way to Venice where his mother was trying to recreate her pre-war life. Exhausted both in body and spirit the pace of the ancient city began to heal him, and when he met Claudia, an Italian Jewess, he was ripe for seduction. Claudia's war had been worse, and after Mussolini's downfall she was quickly betrayed to the SS. While she survived, her father didn't, and to her horror she discovers that the man who was responsible for them being sent to the camp is about to become her new lover's step-father.

In a violent confrontation Adam and Claudia are left needing to create an unbreakable alibi, which they do, but to uphold it Adam must establish what really happened to these people and in doing so exposes the ambiguity of morality in peace and in war, and has to grapple with the questions of what is good or evil, what is right or wrong, and does truth really matter?