Preston, a City of London banker, Ralph Richardson returns to his suburban Kent home on a Tuesday evening to discover that he has been missing for 24 hours and cannot remember the lost day. The mystery deepens as he learns he was seen at the social club where he serves as treasurer, allegedly taking £515 from the safe, and the very man who witnessed it, Robinson, is later found murdered in an allotment. The sequence of events pulls Preston into a tightening web of suspicion, memory gaps, and dangerous possibilities.
When questioned by the police, Preston lies about spending the night somewhere else, a detail that gnaws at him as he realizes the friend he named is away on holiday. The story follows his slow, uneasy efforts to reconstruct what happened, even as the truth remains stubbornly out of reach. He begins to experience flashes that hint at someone following him, and he turns to his doctor for help unraveling the fog of memory that surrounds the lost hours.
The doctor guides him to his solicitor, the man known as Petheridge [Frederick Piper], who urges a pragmatic course: hire an expensive counsel to defend himself, and most importantly tell the police the true story. Yet Preston’s situation grows more perilous as the investigation tightens around him, making him the principal suspect in both the robbery and the murder, even though he cannot be sure of his own involvement.
As the case unfolds, the police collect the clothes and shoes Preston wore on Monday, while his wife, Janet Preston [Margaret Leighton], gradually reveals a burdensome slice of family history. She discloses that money troubles shadowed him because his father had embezzled funds, a revelation that thickens the motive and complicates the web of possible culpability surrounding the weekend’s events.
A crucial clue arrives from a barmaid who shares that Preston has a daily routine between 5 and 6 pm in a nearby pub. He followed this pattern on Monday as well, but a loud bang outside triggers a wartime memory that makes him briefly believe the war has returned. He is placed in a hotel room to sleep, where he remains through a long morning, and only when he is brought to the bar at 5 pm does the trance break and he declares that he is going home. This moment shifts the trajectory of the investigation, and those following the case begin to reevaluate the bits of memory Preston has managed to recover.
In the end, the authorities reveal a clearer picture: Robinson and another unnamed person were responsible for the robbery, and the other person was the one who killed Robinson. The cloud of doubt that hung over Preston begins to lift, though the emotional and financial pressures of the past linger, coloring how he understands the day he cannot remember and the choices he made in the minutes that followed. The film leaves viewers with a measured, restrained portrait of memory, guilt, and the uneasy line between truth and accusation, framed by the quiet urgency of a man trying to piece together a day that refused to stay forgotten.
