Wilful behaviour - Donna Leon

When one of his wife's Paola's students comes to visit him, with a strange and vague interest in investigating the possibility of a pardon for a crime committed by her grandfather many years ago, Commissario Brunetti thinks little of it, beyond being intrigued and attracted by the girl's intelligence and moral seriousness. But when the girl is found dead, clearly stabbed to death, Claudia Leonardo suddenly becomes Brunetti's case, no longer Paola's student. Claudia seems to have no discernible living family - her only familial relationship is with an elderly Austrian woman, who was the lover of her grandfather, but was not herself Claudia's grandmother. Brunetti is both intrigued and stunned by the extraordinary art collection the old woman keeps in her small, unprepossessing flat, and when she in turn is found dead, the case seems to have be about to open up long buried secrets of collaboration and the exploitation of Italian Jews during the war, secrets few in Italy are happy to explore...