When the ex-Queen Nicoletta of Hirtenstein, Gregory's redoubtable grandmother, summons him to Rome, he is powerless to refuse. She is redecorating the villa of an Italian politician, Signor Ardicci. A Russian painting, belonging to Signor Ardicci's opera singer wife Rini, has disappeared. It appears that the value of the artwork lies in the diamond frame that Rini had made for it. Greg is initially reluctant to get involved, not least because of the Ardicci family's refusal to involve the police. But when his long-time companion, Liz Blair, agrees to accompany him to Rome, Greg is persuaded. It's not long, though, before he realises the goings-on at Villa Stefani are more complex and frightening than at first appeared.