Fat Boy McMaster is a hopeless heavyweight boxer, but he has managed to become champion of Ireland, and his devious manager has succeeded in setting up a gigantic payday (largely for himself, admittedly) with a St Patrick's Day fight in New York against Mike Tyson. Journalist Dan Starkey is hired to write the book of the whole affair. Starkey tries to persuade his wife Patricia to give their marriage another try, but he has not succeeded before boarding the plane for the Big Apple with McMaster and his deeply suspect entourage. Once there McMaster's wife is kidnapped, almost every interest group is outraged, the Champ is chased all over town by gunmen of varying allegiance, Starkey's marriage is saved - and, yes, there is the Big Fight to consider too!