In November 1945 corporals Harvey Moon and Lou Lewis return to London from Bombay, where they sat out the war as stores clerks. Harvey's house has been destroyed - not by a bomb but his wife; Rita's incompetence with the gas cooker; and his family have moved to a pre-fab.
Since he was reported missing, Rita believed him dead and would have married a Yank, had he not already had a wife. Unlike his young daughter Maggie and ten-year-old son Stanley,Rita is not welcoming and Harvey and Lou move in with Harvey's mother.
Harvey decides to spend a Saturday with Stanley and take him to watch the Arsenal play football. However, since Harvey went away the team's ground has been turned into a bedding centre and they are sharing a pitch with Spurs - the crowning insult for Harvey, who refuses to set foot in an enemy ground.
To get back in Stanley's good books, he raids Rita's larder of the tinned treats provided by her American boy-friends and provides a slap-up tea.
Maggie goes on a date with Lou and he stays the night.
Harvey and Lou go to Bedfordshire to get officially demobbed, where Harvey, a non-smoker, uses his cigarette allowance to get Lou off a charge.
Back in London, Harvey finds that Stanley has been arrested for stealing a packet of cigarettes from a grumpy shop-keeper and again finds that a little bribery works wonders.
Harvey is not happy when Lou brings home a stack of black market sugar. He is no happier when the Labour Exchange get him a job as a stores clerk and he learns that Stanley is truanting. When he learns that Stanley only goes to school when there are sweet desserts he finds a solution for two of his problems, and quits his job to solve the third.
To reward head mistress Harriet for giving Stanley extra work to get him into grammar school, Harvey Harriet to an upmarket restaurant but feels out of his depth and walks out.
He is almost reconciled with Rita after beating up one of her fancy men who has assaulted her, but comes to see that she was just using him and returns to his mother's where Harriet brings him the food from the restaurant for a late night supper together.
With Christmas approaching Harvey is anxious to get Stanley a bike courtesy of one of Lou's spiv friends and works long hours as a department store Santa to get the money, though Stanley runs back to his mother after seeing Harvey kiss Harriet.
Harvey is almost rumbled when Rita brings Stanley in to the store, but, when Harvey's mother goes to see Rita to propose a Christmas truce, Stanley overhears what his father has done for him and returns to spend Christmas with a drunken Harvey.