Clare Riordan and her son Mikey are abducted from Clapham Common early one morning. Hours later, the boy is found wandering disorientated. Soon after, a pack of Clare's blood is left on a doorstep in the heart of the City of London. Alice Quentin is brought in to help the traumatised child uncover his memories—which might lead them to his mother's captors. But she swiftly realises Clare is not the first victim...nor will she be the last. The killers are driven by a desire for revenge...and in the end, it will all come down to blood.