Saturday evening at Campo Santa Margherita. After a drink, a few locals persuade two American tourists to take a spin in the lagoon. In the darkness the boat hits a pole and the two women end up unconscious on the jetty in front of the Ospedale. Why did no one call an ambulance? And was this really just an accident? The more Commissario Brunetti investigates, the closer he gets to a shocking truth ... Brunetti's 30th case.