In the pitch dark 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. Yet more disturbing is the discovery a day later of the matching hand - indications suggest that the victim was still alive when they were removed. Flea and DI Jack Caffery soon establish that the hands belong to a boy who has recently disappeared. Their search for him - and for his abductor - lead them into the darkest recesses of Bristol's underworld where drug addiction is rife where street-kids sell themselves for a hit and where an ancient evil lurks.