At Firenze, the reclusive artist Adrian Delafield's Florentine enclave in St John's Wood, the whispers of an impending tragedy are growing louder. The tension between the fanatical zealot of a housekeeper Miss Trimming and Delafield's sister Virgilia is just shy of fever pitch, when a cold morning at the house finds Trimming and Adrian sprawled at either end of the staircase upstairs, an injury; downstairs, death. The windows and doors were all locked from the inside, and yet Inspector Julian Rivers, trained to see the malice behind deadly accident, suspects that a murderer had a hand in the fell deed.

But if this is true, Rivers is faced with both the inexplicable puzzle of motive, and the task of untangling an impossible crime in Carnac's compelling and twisting 1956 mystery exploring the demands of kinship, art-world secrets and religious mania.