Harold Shand (Bob Hoskins), a London gangster, is aspiring to become a legitimate businessman and is trying to form a partnership with the American Mafia, with a plan to redevelop London Docklands, including building a casino.
The opening scenes of the film depict a man delivering money in a suitcase to an unknown destination in Belfast. Before delivering the money, the man helps himself to some of the cash. Once the money is delivered, the recipients realise they've been ripped off but are suddenly attacked and killed. Soon afterwards, the delivery driver is kidnapped and killed and subsequently, the man who delivered and stole the money is killed whilst swimming.
Harold is the ruling kingpin of the London underworld and is preparing for a visit from representatives of the Mafia from New York, who he hopes to persuade to go into partnership with him. However, his world is suddenly destabilised by a series of unexplained murders (including Harold's best friend Colin, who was the person killed at the swimming pool) and exploding bombs from an unknown foe. He and his henchmen try to uncover his attackers' identity whilst simultaneously trying not to worry their American visitors. Harold rightly realises if the Americans think he's not in full control of his affairs, they won't go into partnership with him. This becomes impossible when a pub in which they are about to have lunch is blown up. This forces Harold's girlfriend, Victoria, to tell the Mafia representatives Harold is under attack but from an unknown enemy. Victoria tries to reassure the Americans Harold is working hard to quickly resolve the crisis. At this point, Victoria starts to figure out Harold's right hand man, Jeff, knows more than he had been letting on about who might be behind the attacks. Jeff begins to realise Harold might be onto him and tries to prevent people talking through intimidation, including nailing a security guard to the floor.
After some further detective work, Harold then confronts Jeff, who confesses he sent Harold's long term friend Colin on a job to Belfast to deliver money raised by Irish Navvies (construction workers) to the IRA. When Harold discovers Jeff had accepted a job to deliver funds to the IRA, he becomes extremely angry and vows to destroy the IRA in London. Jeff advises against this and then explains the IRA aren't just annoyed about the £5,000 they are missing, they are wrongly holding Harold responsible for the murder of the 3 IRA men seen at the start of the film. Harold loses his temper and - realising Jeff isn't to be trusted - kills him with a broken whisky bottle.
Harold then tries to get even with the IRA and sets up a meeting with them, which Councillor Harris reluctantly agrees to organise. Harold appears to offer them £60,000 in return for a ceasefire but double crosses them, having them shot when they are counting the money.
Having taken out the top men, Harold sees his problem as solved. He then travels to the Savoy Hotel to share this good news with his Mafia partners. When Harold arrives, he finds the Americans are preparing to leave, having been spooked by the attacks from the IRA. Harold then delivers a short but powerful speech to the American Mafia representatives, telling them he has lost all respect for the Mafia and accuses them of American arrogance. He also tells them he has new, German partners and their services are no longer required.
In the closing scene, Harold then leaves the hotel and waits for his chauffeur and body guard, Razors to pick him up. However, when he gets into the car, Victoria has disappeared and the vehicle is being driven by two IRA men. One of them (Pierce Brosnan) has a gun trained on Harold. As the car speeds away, Harold realises he is sure to be murdered and sits in silence, displaying a range of emotions.Bob Hoskins – Harold Shand
P. H. Moriarty – Razors
Helen Mirren – Victoria
Dave King – Parky
Bryan Marshall – Harris
Derek Thompson – Jeff
Eddie Constantine – Charlie
Paul Freeman – Colin
Stephen Davies – Tony
Brian Hall – Alan
Paul Barber – Errol the Ponce, a police informant
Many of the actors playing these un-named parts became famous for their later work.Karl Howman – a Detective Sergeant who enjoys socialising with the criminal fraternity.
Kevin McNally – seen in a Belfast bar scene
Pierce Brosnan – IRA hitman
Daragh O'Malley – IRA hitman
Alan Ford – member of Shand's gang
Gillian Taylforth – the young woman who finds the security guard nailed to the floor of a disused warehouse
Dexter Fletcher – the boy who asks for money to watch Harold's car
The film was directed by John Mackenzie and produced for £930,000 by Barry Hanson from a script by Barrie Keeffe, with a soundtrack by the composer Francis Monkman; it was screened at the Cannes, Edinburgh and London Film Festivals in 1980.
Under the title "The Paddy Factor", the original story had been written by Keeffe for Hanson when the latter worked for Euston Films, a subsidiary of Thames Television. Euston did not make the film but Hanson bought the rights from Euston for his own company Calendar Films. Although Hanson designed the film for the cinema and all contracts were negotiated under a film, not a TV agreement, the production was eventually financed by Black Lion, a subsidiary of Lew Grade's ITC Entertainment for transmission via Grade's Associated TeleVision (ATV) on the ITV Network. The film was commissioned by Charles Denton, at the time both Programme Controller of ATV and Managing Director of Black Lion. After Grade saw the finished film, he allegedly objected to what he saw as the glorification of the IRA.
The film was scheduled to be televised with heavy cuts on 24 March 1981. Because of the planned cuts, in late 1980, Hanson attempted to buy the film back from ITC to prevent ITV screening the film. The cuts, he said, would be "execrable" and added up to "about 75 minutes of film that was literal nonsense". It was also reported at the same time that Bob Hoskins was suing both Black Lion and Calendar Films to prevent their planned release of a US TV version in which Hoskins' voice would be dubbed by English Midlands actor David Daker.
Before the planned ITV transmission the rights to the film were bought from ITC by George Harrison's company, Handmade Films, for around £200,000 less than the production costs. They gave the film a cinema release.
Barrie Keeffe wrote a sequel, Black Easter Monday, set twenty years after the events of the first film. It opened with Bob Hoskins's character escaping from the IRA after the car was pulled over by police. Hoskins would retire to Jamaica, then return to stop the East End being taken over by the Yardies. However, the film was never made.