Mean, gritty, dirty, and low - and that's just Policeman Gary Keltie (Ken Stott) out for retribution for the horrendous crimes against the helpless people of Edinburgh, Scotland during the 1970s by notorious, torturous, and killer debt collector Nickie Dryden (Sir Billy Connolly). This is as hard as they come; giants of their professions, one with a trade that needs to be kept secret, and the other holding a grudge. Shot around the City of Edinburgh, with its coarse language and criminal underclass, we see the wrath of spite, hate, jealousy, and violent vengeance all in the final showdown of justice, and with it, its uncompromising final debt to society.

Hallam's talent for spying on people reveals his darkest fears-and his most peculiar desires. Driven to expose the true cause of his mother's death, he instead finds himself searching the rooftops of the city for love.