A married drunk (Thewlis) hooks up with the ex-girlfriend of a viscious local criminal (Isaacs). He gets booted out of home for his infedelity, has a murderer on his tail, and must try to write the story of his life in order to save his journalism job. He gets help from a stripper dressed as a nun (Griffiths) and goes undercover dressed as Shaggy from Scooby Doo. He finds a drinking buddy in an American fellow journalist.

Plot from imdb, not so accurate though.

Belfast, Christmas 1999. A poor, badly dressed woman is half walking, half stumbling down the road. She is tearful and her behaviour is so disturbed that passers-by look furtively at her before hurrying on. Her walk is purposeful though. She is hurrying to go somewhere specific. She stumbles towards a church that is lit up. As she approaches it we see a sign outside announcing "SERVICE FOR PEACE Belfast Christmas together. All Denominations, 8pm"