This series documents the lives of senior agents Bodi and Doyle from CI5 (Criminal Intelligence 5) in the UK, as well as their controller George Cowley. The mission of CI5 is to combat terrorism and similar high-profile crimes. Kaoli is a tough former MI5 agent who personally selected each of his subordinates. Bodi is a cynical former SAS paratrooper and mercenary whose nature is to control violence, while his partner Doyle came to CI5 from the regular police force and is more like an open-minded liberal. Their relationship is often controversial, but they are the top figures in their respective fields and also the ones that Cowley always assigns to the most difficult cases.