The film opens as tube driver Paul Callow (Mackenzie Crook) accidentally runs someone down with his train. A few days later, he has the misfortune to have another one-under. His colleagues tell him about a little known rule at London Underground. The one no-one talks about. THREE under within a month, and you're OUT... earning yourself 10 years salary in one lump sum. This is an attractive proposition for someone with heavy debts and a yearning to escape the stresses of the big city to write a novel.
Paul sets about trying to find someone prepared to die under his train by Monday morning.
Not easy. But the search he embarks on is both hilarious and emotional.
How do you approach a complete stranger and ask him if he fancies dying under your train!?
After many failed and excruciatingly embarrassing approaches; he comes across Tommy Cassidy (Colm Meaney) attempting to jump off Holborn Viaduct.
To Paul's amazement, Tommy agrees to his outrageous proposal. The incentive? Enough money for a last weekend to tie up the loose ends of his life. Once it's agreed, Tommy is determined to go through with it: A deal is a deal.
With a new suit and a hired car, Tommy travels to the Lake District via Liverpool so that he can try and reconcile things with his wife, Rosemary (Imelda Staunton) whom he walked out on 8 years ago, and his feisty daughter Frankie (Gemma Arterton). And Paul tags along to protect his investment.
We encounter a host of other characters on the way including the Callaghans, (Annette Badland) and (Gary Lewis), who have something that Tommy needs which leads to a very slippery situation; Mary, (Kerry Katona) an angry mistress; Vic (Mark Benton) a fellow tube-driver and expert on the Three and Out Rule; and Maurice, (Sir Antony Sher) a French chef with culinary designs of a very unusual nature.
As the film progresses, Paul and Tommy each find something that has eluded them both for years - true friendship. Tommy also has to deal with the inevitable wrath of his wife, who for the past 8 years thought he was dead; as well as his daughter Frankie who wishes he was! Its a life-changing weekend for all concerned.
On Monday morning, they are back to the reality of the deal they struck. And a deal is a deal.
But can they go through with it?