In a British Army "glasshouse" in the Libyan desert, prisoners convicted of service offences such as insubordination, being drunk while on duty, going AWOL or petty theft etc. are subjected to repetitive drill routines as a punishment in the blazing desert heat. The arrival of five new prisoners slowly leads to a clash with the camp authorities. One new NCO guard who has also just arrived employs excessive punishments, which include forcing the five newcomers to repeatedly climb a man-made hill in the centre of the camp. When one dies, a power struggle erupts between brutal Staff Sergeant Williams, humane Staff Sergeant Harris, Regimental Sergeant Major Wilson and the camp's medical officer as they struggle to run the camp in conflicting styles. Roberts is a former squadron sergeant major from the Royal Tank Regiment, convicted of assaulting his commanding officer – which he explains to his fellow inmates was because he was ordered to lead his men in a senseless suicidal attack. Roberts openly scorns Williams's brutality and serves as challenge to his authority. The RSM is a career soldier, powerful within the prison in which he is working, but realistic, "No one's going to pin a medal on us". However, he sees his duty to be as important as any other – that of breaking down failed soldiers, then building them back up again, in his words, "Into men!" Staff Sergeant Williams is new to the prison, and his ambition is matched only by his cruel treatment of the prisoners; he seeks to use their suffering as means for promotion. When Roberts is accused of cowardice, he asks Staff Sergeant Williams, "And what are you supposed to be – a brave man in a permanent base job?" The RSM also questions Staff Sergeant Williams's motives for getting out of London, as in another scene, he slyly mentions the fact that the Germans were bombing the UK just as Williams was volunteering for prison duty in Africa. Staff Sergeant Williams openly admits that he is trying to impress the RSM by showing that he has got what it takes to do the job, and attempts to undermine the RSM with a late night drinking contest. Staff Sergeant Harris is the conscience of the prison who sympathises with the men, too closely, according to the RSM. The officers, both the CO and the medical officer, take their duties casually and, as Roberts points out, "everyone is doing time here, even the screws". In the finale, the camp's medical officer and Staff Sergeant Harris decide to report the abuses at the camp. Sadistic Staff Sergeant Williams goes to administer one final, perhaps fatal, beating to Roberts, when two prisoners intervene and appear to attack and very severely beat Williams. Roberts pleads with them to stop, knowing that if the prisoners beat up a prison officer, then any case they may have had against them is hopelessly lost, they are still prisoners, and the prison staff have a much stronger hand to inflict whatever cruelty they now wish to.
The film was based on a screenplay by Ray Rigby, who wrote for TV and had spent time in military prison. Movie rights were bought by Seven Arts Productions, which had a production deal with MGM. Producer Kenneth Hyman arranged for Rigby's script to be rewritten by other people, but when Sidney Lumet came on board as director, Lumet went back to Rigby's original draft. He and Rigby did cut out around 100 pages of material before filming. "There really isn't a lot of story", said Lumet. "It's all character – a group of men, prisoners and jailers alike, driven by the same motive force, fear." Sean Connery agreed to play the lead because it represented such a change of pace from James Bond. "It is only because of my reputation as Bond that the backers put up the money for The Hill", he said. Lumet says he told Connery before filming began that, "'I'm going to make brutal demands of you, physically and emotionally', and he knew I'm not a director who has too much respect for 'stars' as such. The result is beyond my hopes. He is real and tough and not at all smooth or nice. In a way he's a 'heavy' but the real heavy is the Army." Filming took place in Almería, Spain starting 8 September 1964. An old Spanish fort in Málaga was used for the prison. Many people associated with the production had regarded the filming as pleasant, despite difficult conditions: Temperatures went above 46 °C and nearly all the cast and crew became ill, even though thousands of gallons of fresh water were brought in. The Hill did not perform well in cinemas, although it received excellent reviews and Ray Rigby's screenplay won at the 1965 Cannes Film Festival. Rigby published a novel of the story in 1965.
