Slade Prison has two new inmates: Rudge, a nervous first offender, and Oakes, an armed robber. Rudge is assigned a job on the prison farm alongside Fletch — who takes him under his wing. [Oakes] approaches the prison's ‘Mr Big’, Grouty — also known as “Grouty” — and, using a cut from his last job before being caught, asks for his escape to be arranged. [Grouty] sets the price, then begins making arrangements.
[Grouty] starts by forcing [Fletch] to persuade the prison governor to allow an inmates-versus-celebrities football match, to boost prisoner morale and “put Slade on the map.” [Fletch] successfully manipulates new prison officer [Mr Beal] to make the suggestion to Mr Mackay, who approaches Governor Treadaway, and the football match is approved, although all three claim the idea was theirs alone. [Fletch] then becomes the prison team's manager; [Grouty] insists that [Oakes] be on the team.
The celebrity team arrive in a coach. The prisoners are notably underwhelmed when it is explained that their hopes for one of The Goodies on the team have not been met, the nearest they have to a famous face being a weather presenter from Anglia Television. During the match, [Oakes] feigns an injury and is taken to the changing rooms where he meets the coach driver; revealed as an accomplice. They exchange clothes and [Oakes] ties the coach driver up to throw off any suspicion. Shortly afterwards, [Fletch]’s cellmate [Godber] is concussed on the field so Fletch takes him to the changing rooms, where he sees the ruse unfolding. Taking no chances, [Oakes], now disguised as the coach driver, forces [Fletch] and a dazed [Godber] into the coach's luggage compartment at gunpoint then drives out of the prison under the guise of topping up the fuel.
Out into the country, [Oakes] meets further accomplices and abandons the coach; they drive [Fletch] and [Godber] away in a motorhome. Meanwhile, the prison officers have discovered the escape: the police and the Home Office are informed, both searching for the coach; though the prison officers' attempt to help isn't well-met with police, as no-one can explain how they let three inmates drive out of the gates. [Fletch] tells [Oakes] that they don't want to escape as he and [Godber] only have a short time left to serve, and that they won't tell anyone about [Oakes]'s plan because it's ‘Them and Us’.
[Oakes] relents and releases them and they find a barn to hide in and catch their breath; [Godber] recovers from his bang on the head and they help themselves to some apples. [Fletch] explains to [Godber] that there is no possible way that being caught outside ends well for them, as any policeman they approach will claim the find for himself. Furthermore, he realises that once [Governor Treadaway], and [Mr Mackay] start passing the idea of the match back down the line, it'll end up with [Fletch] looking like the responsible one and he'll serve more time, meaning the only solution is to break back into prison.
Making their way through fields and villages, they steal a sexton’s bicycle, find the abandoned coach and manage to sneak back into the luggage hatch just as the police let the prison officers take it back to the prison. Once inside the prison walls, both convicts slip out of the coach and smuggle themselves into the prison officers' club storeroom, where [Fletch] quickly consumes several bottles of alcohol to become inebriated enough to make their story pass: they stumbled on [Oakes] tying up the bus driver and he forced them down the delivery hatch, where they claim to have been since.
The story is believed by the Governor and life seems to return to normal. As the other inmates question [Fletch] on what really happened, [Grouty] subtly tells him that he will be rewarded for his efforts and for keeping his mouth shut, and [Rudge] thanks [Fletch] for helping him through his time inside. Later in their cell, [Godber] is jealous at [Oakes] having got away, though [Fletch] assures him that it won't matter: [Oakes] will hate being on the run. [Fletch] reminds [Godber] that in a few months, he'll leave prison as well: the difference being that he'll be free and clear.
Mr Mackay visits them and tells them that, while the Governor believes that they have been locked in the storeroom all day, it doesn't explain the mysterious “UFO” sightings in the village (unidentified flying objects), and the various happenings that they created on their journey. Realising that he will never be believed, Mackay tells them that he will always be watching, and that his day will come. [Fletch] and [Godber] cheekily munch on the stolen apples once Mackay turns his back to them.
