For the first time ever, a Metropolitan Police undercover detective has broken ranks to reveal the stark reality of life in the police force today. Duncan MacLaughlin was one of New Scotland Yard's elite. In a career spanning more than two decades he served in both the Central Drug Squad and the Regional Crime Squad - Britain's equivalent of the FBI. Trained in in SAS covert techniques, his expertise lay in money laundering and undercover surveillance. Infamous cases in which he was involved include the investigation of Kenneth Noye, the pursuit of kidnap victim Stephanie Slater, the murder of PC Keith Blakelock and Operation Emerge - the seizure of a tonne of cocaine, tracked from South America. He and his colleagues penetrated international drug cartels and nailed the ruthless barons who controlled them. Filled with black humour, gritty slang and investigative detail that only an ex-copper could reveal, MacLaughlin's story is a riveting insight into the world of serious crime that is both thrilling and frightening. With shocking behind-the-scenes stories that you'll never read in the newspapers or see on Crimewatch, The Filth is the true story about working on the dark side of the streets.