Capitalizing on the popularity of the BBC television series, this installment finds "Fletcher" (Ronnie Barker) and his prison companion "Lenny" (Richard Beckinsale) in a Cumbrian jail where they frequently trade barbs with head guard "Mackay" (Fulton Mackay) and outsmart the gentle “Barrowclough” (Brian Wilde). A delivery van arrives one day, bringing two new faces. One is "Oakes" (Barrie Rutter), while the other happens to be a fresh prison officer named "Beal" (Christopher Godwin). It becomes apparent that "Oakes," with some prompting from the unofficial prison director “Grouty” (Peter Vaughan), won’t remain incarcerated for long. Consequently, "Fletch" is prompted to arrange a celebrity soccer game during which their newest inmate will switch places and make his getaway. Predictably, things almost go according to plan, but the unsuspecting "Lenny" accidentally collides with a goalpost, and suddenly they find themselves in the luggage compartment of a bus en route to freedom. Deserted by “Oakes,” they decide that breaking back into the prison is their best course of action. There are some genuinely funny lines and clever verses from Barker, who has excellent comedic delivery as he interacts entertainingly with Mackay, who portrays the self-important warden with considerable talent – both actors demonstrate superb comic timing. Beckinsale isn’t featured extensively in this one, but remains reliably amusing, as does Peter Vaughan playing a refined, opera-loving version of “Mr. Bridger,” and the supporting cast is exceptionally well chosen. Several attempts were made to adapt popular comedies into films during the 1970s, and I believe this is likely the strongest result – it’s still capable of eliciting laughter.

Source on TMDB