The story of two boys living in Portsmouth at the time of the First World War. Jimmy and Reg have no fathers, and help eke out their mothers' paltry wages by mudlarking - scavenging for coins in the black mud of Portsmouth harbour. When they find a skull in the mud, they unleash a chain of events which ends in the boys uncovering a terrible secret of murder. Seven women have been killed - is it Jack the Ripper again? For some reason the authorities are covering up the murders and the boys are arrested and then drafted into the army to stop them talking. Jimmy has been suspecting the king - he's always visiting the troops when the women are murdered, but the truth turns out to be just as shocking.