When her husband becomes involved, Grace is forced to make a difficult decision - turn him in and risk her life, or stay loyal and risk the lives of those she loves .

He discovers that her husband worked for a company that monitored the cleanliness of Venice's water supply and that he had died in a motorcycle accident.

Distracted briefly by Vice Questore Patta's obsession with youth crime in Venice, Brunetti turns to the remarkable research skills of Patta's secretary, Signora Elettra Zorzi.