Customs officer Marcus Ashton joins a new team hunting Britain's most wanted criminals, based on Cameron Addicott's book.

The series is about a Customs Officer, Marcus Ashton (Ash) who is recruited to a new law enforcement team tasked with hunting down some of Britain's most wanted criminals. The series is inspired by the book of the same name which details the career of former customs agent Cameron Addicott, written by Kris Hollington.

Special Agent Marcus "Ash" Ashton (Fagbenle), a HM Revenue and Customs agent and his partner Tommy (Lonsdale) capture a drugs shipper in an operation at London Waterloo station. Whilst his boss is happy with a conviction of 3Kgs of cocaine, Ash wants a larger criminal. During the subsequent operation, Tommy is severely injured in a resultant car accident, and Ash is then suspended. Subsequently he is approached in a pub by Cartwright (Stewart), the head of top-secret UNIT (Undercover Narcotics Investigation Team). On first entering UNIT's HQ he meets a familiar face, his Customs training officer Valerie (Ashbourne).—Soumik Ghosh