There is a string grizzly of killings in the suburbs of London. Detectives can't find any motive behind the murders. A brilliant psychologist helps inspector Bullock to uncover a shocking fact: The cuts on the victims all show the same, exact signature, even though the attacks were carried out by different people. The suspects are left with no recollection of the horror they inflict. Are they terrible liars?, or have they simple gone raving mad?.