Mona Mars’s disappearance

Mona Mars’s disappearance is an unresolved absence that police connect to Rusty Regan’s disappearance, making the missing woman part of a possible elopement story that cannot be verified. The investigation finds Mona at the Casa de Oro, but uncertainty about her identity and whereabouts persists: Eddie Mars protects her privacy, and the available evidence never proves that she left with Regan. The later revelation that Carmen Sternwood killed Regan overturns the apparent explanation, exposing Mona’s disappearance as a misleading parallel rather than the solution to his fate.

A disappearance tied to Regan’s

Captain Gregory’s file places Regan’s departure on September 16. The chauffeur was off duty, and nobody saw Regan take his car. Four days later, police found the car in a garage at the Casa de Oro, a well-appointed bungalow court near the Sunset Towers. A garage attendant reported that the car did not belong there. Investigators could not determine who had put it in the garage, and the prints they found did not match anyone on file.

The abandoned car did not, by itself, establish foul play. Gregory explained that its presence could fit more than one account, including the possibility that Regan had gone away with Eddie Mars’s wife. The case therefore began to turn on a suggestive coincidence: Regan and Mona had both disappeared at nearly the same time, and his car had surfaced at a place associated with her.

What the police could establish

Investigators questioned tenants at the Casa de Oro and learned that Mona was living there. Gregory said that she had left within two days of Regan. Someone had reportedly seen a man who sounded somewhat like Regan with her, but police could not obtain a positive identification. The account supported suspicion without resolving it: the reported companion was a resemblance, not a confirmed sighting of Regan.

That distinction matters to the investigation’s limits. Gregory contrasted the uncertainty of hotel employees who had been shown a clear photograph with the confidence sometimes claimed by witnesses who said they had recognized a fugitive months later. The police had Mona’s reported residence and the timing of her departure, but no dependable identification establishing that she and Regan had traveled together.

A protected absence

Gregory set out a practical theory: Mona and Regan had probably left in her car, which police had not found, and had already had a fourteen-day head start by the time he described the case. He expected that money would eventually expose them. Regan was known to have carried fifteen thousand dollars, while Mona might also have had money or valuable jewelry. In Gregory’s view, even people using new names would eventually need to cash a check, incur a debt, or write a letter.

Mona’s past offered another possible lead, but not one the police could readily pursue. Asked what she had done before marrying Eddie, Gregory answered that she had worked as a torch singer. Marlowe asked whether police could obtain old professional photographs. Gregory said no: Eddie might have had photographs but would not release them, and he wanted Mona left alone. Gregory could not make him cooperate. Eddie and Mona did not live together, though Eddie said they remained friendly; his influence in Los Angeles further constrained the inquiry.

The explanation that fails

The theory of a joint departure remained plausible because it joined the missing car, the bungalow-court residence, the timing, and the reported sighting. Yet each link had a qualification: the car’s depositor was unknown, the supposed companion was not identified positively, and Eddie withheld the materials that might have helped locate Mona. Gregory’s working account was thus an inference shaped by scarce evidence and by the inability to question or trace the people at its center.

The novel ultimately separates Mona’s disappearance from the cause of Regan’s. At the abandoned oil wells, Marlowe reconstructs the day Regan disappeared: Regan had taken Carmen there to teach her to shoot, and Carmen turned the gun on him. That disclosure identifies Carmen as Regan’s killer and dismantles the apparent elopement explanation. Mona’s absence remains significant not because the police theory is confirmed, but because it demonstrates how a real disappearance can supply cover for a false story about another one.