New York Police Lieutenant James Dempsey kills his corrupt partner Joey and has to lay low until the case can be further investigated. His superior O'Grady sends Dempsey to London, England as part of an exchange of officers. Chief Superintendent Spikings, head of SI10 is not to pleased to have a 'yank' forced onto his department. He decides to couple Dempsey with his complete opposite, Sergeant Makepeace, an upper class English rose on a case involving a mysterious shipment of caviar.