A sinister figure stalks the gas-lit groves of Cremorne Gardens, the last pleasure-ground on the banks of the Thames. His weapon, a sharp pair of scissors. His victims, young women in the first bloom of youth. HIs crime - merely to remove a lock of their hair. Inspector Decimus Webb of Scotland Yard suspects a harmless lunatic is at large. But when morbid obsession turns to murder, even Webb's loyal sergeant begins to doubt his judgement.