A refiner's fire

When two teenage gangs are arrested after clashing violently in one of Venice’s campi, the son of a local hero is implicated. But when Commissario Guido Brunetti is asked by a wealthy foreigner to vet this man, Monforte, for a job, he discovers that Monforte might not be such a hero after all. This seeming contradiction, and a brutal attack on one of Brunetti’s colleagues by a possible gang member