The rain that sheets down in nearly every scene of Robert Hamer's 1947 It Always Rains on Sunday is as much a psychological phenomenon as a meteorological one—a bleak, bone-chilling damp born from the bombed-out dreams and desires of a dozen or so characters during a single 24-hour period in postwar London. Based on a novel by Arthur La Bern, it begins as the story of a former barmaid, Rose Sandigate (Googie Withers), who offers safe haven to her former lover, the escaped felon Tommy Swann (John McCallum). But with that desperate situation as its emotional and narrative core, It Always Rains on Sunday fans out into a sprawling, Altmanesque tapestry of East End life that encompasses the barmaid's comely stepdaughter Vi (Susan Shaw); Vi's occasional lover, Morry (Sydney Tafler); his gangster brother, Lou (John Slater), who has eyes for Vi's sister, Doris (Patricia Plunkett); and the flat-footed detective, Fothergill (Jack Warner), who's close on Swann's trail. Like Hamer himself, all meet with something less than a good end.

Born in 1911, Hamer began his career as a film editor before transitioning to Michael Balcon's Ealing Studios, where he got his first shot at directing on a segment of the 1945 horror anthology Dead of Night; his is the one about the haunted mirror that replays the grisly murder it witnessed. Accursed mirrors of a less supernatural variety would go on to figure prominently in Hamer's work, including in Sunday, where the characters frequently stare into their reflections and remember the bygone days before circumstance forged them into hard, embittered creatures of survival.

Today, if Hamer is remembered at all, it's for the next film he made at Ealing, Kind Hearts and Coronets, with Dennis Price as the ostracized noble who must eliminate eight relatives (all played by Alec Guinness) in order to inherit a dukedom. Even in Hamer's own time, its reputation eclipsed that of his other films ("It's flattering to make a picture which becomes a classic within 10 years; it's not so flattering, however, when people get the impression it's the only picture you've ever made," he remarked in a 1959 interview), and it remains the only one of his features widely available on home video.

Yet if Kind Hearts is an undeniable comic triumph, Hamer was ultimately better served by tragedy. It Always Rains on Sunday is a masterpiece of dead ends and might-have-beens, highly inventive in its use of flashbacks and multiple overlapping narratives, and brilliantly acted by Withers and McCallum. Compacted into a breathless 90 minutes, the entire film exists in a state of high anxiety—not a frame is wasted. Finally, day gives way to night, the despair thickens, and all points converge on a fever-dream train-yard finale of long shadows, deep focus, billowing smoke, and rear projection.

This is clearly the work of a tortured soul. A repressed homosexual and a drunk, Hamer made six more features after Kind Hearts without ever equaling that film's popular success or Sunday's artistic one. By the time of School for Scoundrels (1960)—the last film that bears his name as a director—he was collapsing on the set and suffering from horrific delusions (including one of a mutilated lobster chasing him through the streets of London), and ultimately had to be replaced. Three years later, he was dead at 52. But for bad luck and a penchant for self-destructiveness, Hamer might have been one of the major figures in modern British cinema. As things stand, It Always Rains on Sunday is a major work, badly in need of rediscovery.