Brunetti would like to have as little as possible to do with the the old-established families. The Commissario however, cannot refuse The venerable Contessa Lando-Continui, an request. The 80-year-old urges him to investigate a family tragedy, that was hushed up 15 years ago. Her granddaughter, who almost drowned in a mysterious fall into the canal, has lasting damage from brain injuries. Manuela, now 30 years old, is and will always be on the mental level of a child! When her then saviour is stabbed, Brunetti finds himself in the middle of a murder case. In his investigations he does not stop at the family, the confidants and the business of the mighty Contessa. He wants to find out the whole truth.