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 container of Clare's blood is left on a doorstep in the heart of London.

Psychologist Alice Quentin is brought in to help the traumatized child uncover his memories, with the hope that it might lead the authorities to his mother's captors. But Alice swiftly realizes Clare is not the first victim... nor will she be the last.

The killers are desperate for revenge... and in the end, it will all come down to blood.