World War Two, circa 1942. A British convoy of army trucks threads its way through a North African desert prior to combat. Ordered to destroy any personal documents, soldiers Harry Fife and Art Wallace examine a group photograph taken after they had finished basic training in England.

Some months earlier. The group - the 'new lot' - are still civilians, none of them happy to find themselves conscripted into the army. Harry has experience in Civil Defence; the worried Art works as a nightclub waiter. Barrington, middle-class, with airs and graces, is in business; Ted Loman is a feisty bricklayer. Keith Bracken, a sensitive type, lives with his mother. They meet, grumbling, on the train taking them to their army camp; another passenger in their carriage is a Czech soldier, who sobers them with his personal history.

On the first night, Harry finds Art trying to leave camp, and persuades him to stay with the Czech soldier's words: "We're all in it together". A widower with two children to care for, Art is concerned about their welfare; behind the scenes their supervising corporal, a terrier on the parade ground, helps him find an amenable solution. Ted, the group's awkward cuss, has his own teething troubles, but begins to be a team player when he helps the nervous Keith overcome his fears firing a Bren machine gun. Cast in the role of German parachutists, the group take part in a Home Guard exercise, with Art as their initially reluctant leader; but strategic thinking and teamwork brings them victory and the capturing of their opponents.

With their training period at an end, the men relax at the local cinema, where a British war film, starring Robert Donat, is playing. The character's foolish and unreal behaviour stirs them to derisive laughter. After their group photograph is taken, the five men ponder on the effects of their six weeks at the camp, and the need for people to continue working together once the war is won. Back in the desert, in the convoy truck, Harry tears up the photo. Over the radio, the BBC announcer reports a speech by the Prime Minister, Winston Churchill, underlining the role that teamwork and training has played in the British forces' advance.