Sunday in London's drab East End, shortly after World War II. Rain starts to fall. In Coronet Grove, a young woman, Vi, is seen by her father, George Sandigate, dashing from a car in the early hours. At a nearby coffee-stall, three low-life types, Whitey, Dicey, and Freddie, prepare to go off on a 'job'. As morning arrives, ex-barmaid Rose Sandigate wakes her stepdaughter Doris to fetch tea and the paper. Her humdrum life is disrupted by the news - and soon the arrival - of escaped convict Tommy Swann, her former fiancé, whom she'd met while working at the local pub. She remembers her time with Tommy, and the ring he gave her, shortly before his arrest.
Over breakfast the family relations are tense, and Rose goes to retrieve some old black-out material from the air-raid shelter, where she finds Tommy hiding. Promising to help, she returns to the kitchen on edge, and then has to suffer delays while the family run through the Sunday rituals (son Alfie going out to play, George bathing, Doris preparing for a day trip, and Vi off to meet the driver of the sports car) before she finally succeeds in smuggling him into the house to feed him and dry his clothes, all the while risking discovery. She takes him food and he asks for money. When Rose offers him the ring, kept in her drawer, he is grateful, but fails to recall its significance to her.
Meanwhile, Vi visits the sports car driver, Morry Hyams, a local bandleader/music-store owner who regularly cheats on his wife; she goes to his shop following up last night's invitation. Doris encounters Morry's brother Lou at his amusement arcade, but eventually rejects his advances, preferring her rather stolid boyfriend and a 'safe' job, though not before she and her boyfriend row about it. Alfie gets drawn into blackmailing Morry for a free mouth organ when he spots Vi and Morry embracing in the record booth.
The police have two cases to follow: looking out for Swann, and following up a robbery the night before. They encounter most of the colourful characters in the area, including a doss-house proprietor, the inept local villains Whitey, Dicey, and Freddie, a fence and Slopey Collins, the local reporter.
Rose sits anxiously through the family Sunday dinner, with Swann still upstairs. His presence is nearly revealed several times, particularly following a row involving Vi, Doris and Rose which takes place outside the locked bedroom where Swann is hiding. Evening finally arrives and, with George at a darts match and the girls out, Swann can make his get-away. Rose is wrestling with the idea of resuming their former relationship, but local reporter Slopey Collins has worked out where Swann has been hiding and calls at the Sandigate's: Alfie opens the door and as Rose shoos him back to bed Swann rushes Slopey and his cover is blown.
A chase follows with Swann's path crossing the police as well as that of the murderous Whitey and his victim. Meanwhile, Rose attempts to gas herself in the kitchen. Finally Swann is trapped in a railway goods yard and recaptured.
George visits Rose in hospital and entreats her to get better quickly, before walking home down the wet streets.
