Nine feet under water, police diver Flea Marley closes her gloved fingers around a human hand. The fact that there's no body attached is disturbing enough, until the discovery of the matching appendage a day later. Both hands have been freshly amputated, and there are indications that the victim was still alive when they were removed. Newly seconded to the Major Crime Investigation Unit in Bristol, DI Jack Caffery soon establishes that the hands belong to a young man who has recently disappeared. As Caffery and Marley search for the rest of the victim and for his abductor, they journey into the darkest recesses of Bristol's underworld, where drug addiction is rife, street kids sell themselves for a hit, and a disturbing occult ritual may be making an unexpected appearance.