Marcus Ashton is a law enforcement officer who takes crime personally. He’s committed and uncompromising in fighting it on the same streets where he grew up. After 15 frustrating years of low-level drug busts, he finally sees a chance to fulfil his dream of taking down the underworld’s biggest players when he is recruited by the UNIT (Undercover Narcotics Intelligence Team). Using state-of-the-art surveillance, this highly skilled and determined squad are single-minded in their mission to hunt down and bring to justice London’s most ruthless criminals.