DS Jake Brown (Eamonn Walker) and DI Carl Harrington (Ade Sapara) are both police officers, but the similarity stops there. Jake is streetwise, tough and already a top undercover officer specialising in drugs. Harrington is Cambridge educated, squeaky clean, and on the fast track to a desk job at the top. But when Harrington decides he wants to gain credibility by working drugs, they are thrown together in a dangerous undercover operation in Manchester's seedy druglands.