As Commissario Guido Brunetti watches his mother buried, he takes some solace in the cloud dappled sky, the tops of the Venetian cypress trees, moving gently in the spring breezes. As ever, his wife Paola is at his side. 'There's nothing to remember about her except the good', she says. And that, thinks Brunetti, is exactly right.

But then a ten-year-old gypsy girl, Ariana, is found dead in the canal, in possession of a man's watch and wedding ring, and the pathologist Pucetti further reports that she was suffering from the effects of a sexually transmitted disease. On the paving stones, Ariana looks for a moment like a fairy tale princess, a halo of tangled golden hair radiating out from her sleeping face - a face that Brunetti begins to see, in his dreams.

To investigate Brunetti infiltrates the community of gypsies, or 'Rom', in official police parlance, living in camps out near the Dolo. But there's nothing official about the young Rom children sent to rob rich Venetian homes, and Brunetti struggles with institutional prejudice, the entrenched bureaucracy of expedience, and his own troubled conscience, as he tries to understand.