In Pursuit of the Two Legged Mule is the true story of the war waged by Officers of Her Majesty's Customs and Excise at Heathrow Airport against the international drug smuggler. The smuggler, or mule, as he or she was generally known, was devious and determined, but so were the Customs Officers. The book shows how the officers kept up with the ever changing methods of concealments, how they learnt to adapt to each new challenge. For example when internal concealments, swallowers, appeared on the scene, the immediate dilemma was. "Just how do we retrieve the packages of drugs?" The story is told from the viewpoint of the officer in the Terminals or on the Tarmac areas at Heathrow. It shows them as just normal people, with everyday problems, carrying out a difficult job. It explains the thought processes that lead to an interception and an arrest. It is told with the same high degree of humour that was displayed by the officers as they carried out their arduous and sometimes dangerous duties.