Maurice Pogue wakes up to a troubling truth: he suffers from retrograde amnesia, forgetting everything that happened the day before. A self-made recording reveals that he is a Los Angeles–based private investigator, and that the memory loss followed a case-related injury. He resolves to hide this condition because, in his own story, he is the key witness against the man responsible. The recording mentions a mysterious woman, Sarah Novak, who has been living under the alias Beth Holly in San Francisco and has traveled to LA because she is being blackmailed.
The police arrive at Pogue’s office and escort him to a birthday party they’ve arranged. At the party, he confides in his friend John Dolby that he has seen Sarah, and Dolby then reveals that Sarah is dead. The social gathering becomes a tense backdrop as Pogue realizes the stakes of his condition, and the truth behind Sarah’s appearance starts to surface.
During the same evening, Pogue encounters a physician he knows as Dr. Doover who claims to simply understand the condition rather than solve it. The doctor’s limited knowledge deepens the mystery, while two henchmen take Pogue away to meet Cornell, the man he is supposed to testify against. Cornell tries to buy his silence with a substantial payoff, pressing Pogue to deny any involvement in the crime.
Back at the records, Pogue uncovers a web of past and present deceptions: Sarah was Cornell’s lover and had decided to testify against him, fearing for her life. She had hired Pogue to protect her, but she was killed by a car bomb—the same blast that caused Pogue’s amnesia. Before she died, she left a clue about a coin she had stolen from the L.A. County Museum, a token that she claimed would lead to the truth. The only hint to its location is the word “Baby” that Pogue once uttered when she handed it to him.
The trail heats up the next day when Pogue forgets again, and Cornell’s men arrive to press for a sworn statement. Mistaking Cornell for his landlord, Pogue hands over a rent check instead and struggles to figure out where the coin is. He reunites with the woman who has been posing as Sarah, and they share a night together. When he awakens, memory returns in full. He recalls hiding the coin in its collar after learning his dog is named Baby. He drags his memory forward, taking Sarah to a pay phone to contact the blackmailers, and notices that Beth Holly’s handwriting does not match the note that wrapped the coin. Realizing that the woman in his life is not Sarah Novak, he understands she is Beth Holly, hired by Dr. Doover to impersonate Novak. Cornell’s men kidnap Beth when they catch her in the car.
On Thursday morning, Cornell abducts Pogue and subjects him to torture to extract the coin’s location. The pair escapes and races to the courtroom for Cornell’s trial. In a pivotal moment, Pogue’s memory returns as a fall in the courtroom leaves him with clarity; he explains to Beth that the coin was placed in a parking meter, and she speeds off to recover it. Pogue testifies against Cornell, prompting a plea change from the defendant. After the verdict shift, Pogue reunites with Beth at his apartment, and they share a quiet kiss before going inside, the case resolved but the memory of the days that led there forever settled in his mind.
