Murder at Glen Athol

Famous detective Bill Holt goes on vacation to write a novel in the home of his friend, Judge Hammond, who is out of town. Muriel Randel, who lives next door with her wealthy in-laws, invites Holt to a party. There Holt meets Ann Randel, Muriel's mother-in-law, who supposedly adores her; Ann's brother, Reuben Marshall, who is suspicious of Muriel's antics; Jane Maxwell, whom Muriel's second husband, Harry Randel, was going to marry before Muriel married him and drove him into the nearby Piermont sanitarium; Harry's younger brother Tom, with whom Muriel is currently having an affair; and Muriel's first husband, Campbell Snowden, from whom she received a $250,000 divorce settlement. Muriel is currently blackmailing nightclub owner and bootlegger Gus Coletti with letters and a bounced check that prove that he hired a "hit man" to murder his competitors. The night of the party, Muriel inveigles Coletti into delivering Jamaican rum to the Randels' and demands more blackmail money. Upon his arrival, Coletti lunges at Muriel in an attempt to retrieve the papers from her cleavage, and Holt intervenes and knocks Coletti out. At midnight, when Muriel returns to the party, Ann hands her a cup of rum coffee, but she soon tires and Ann helps her to bed. At four a.m., Jane sneaks into Muriel's room and steals a string of pearls she got from Snowden when they were married. Holt, asleep next door, is awakened by a shot and, rushing to the Randels', discovers that their butler, Simpson, after hearing what he thought was a prowler on the roof, shot Harry, who escaped from the asylum, sending him to his death from the roof. As Harry dies, he confesses to Ann that he killed "that dirty cur," but it is unclear to whom he is referring. When the rooms are searched, Muriel is found dead with a cut throat, and Snowden is found dead from a fractured skull. Jane, who has fainted, is found next to Snowden, as is a bloody dagger. Holt's faithful man-servant, Jeff, finds a carnation near Snowden's body, and Holt remembers that Coletti was wearing one earlier in the evening. When the police and the district attorney arrive, Marshall, who is well connected with the authorities, pronounces Harry the murderer, and the police are prepared to close the case. Jane, however, pleads with Holt to clear Harry's name. As the police gather evidence, they discover Muriel's pearls missing and find an iron pipe outside the house that has hairs on it. When Holt visits Harry's doctor at Piermont, he learns that Jane had visited Harry the day he escaped and her visit had so enraged Harry that he had bludgeoned the doctor's dog to death before escaping. Later Jane confesses to Holt that she stole the pearls at the request of Harry, who thought of them as a "badge of infamy" for Muriel, who had refused to return them to Snowden following their divorce. When Coletti tries to hold Holt hostage, he escapes, and in an ensuing gunfight, the car of Coletti and his henchman, Tony Cosmano, overturns. The next day, the newspapers pronounce Cosmano dead and report that Coletti is seriously injured. When Marshall visits Coletti in the hospital, Coletti swears he did not kill Muriel, but, after entering Muriel's room the night of the murder to find the letters, was caught by Snowden. When he saw the dagger he had given Coletti earlier, Snowden assumed Coletti had killed Muriel and ran into the hall to call for help. Coletti followed and struck Snowden over the head, then dragged him into his room, placing the bloody dagger next to Snowden's body to implicate him in Muriel's murder. Meanwhile, Holt remembers that when the victims were found, Snowden's body was limp, while Muriel's was stiff, suggesting that Muriel was killed three hours before Snowden. He then questions Simpson again about the night of the murders: Simpson had seen Ann saying goodnight to Muriel from the hallway through the door to Muriel's bedroom, which was ajar. Although Ann had given Simpson the impression that Muriel had responded to Ann, she was in fact already dead. When Coletti had delivered the champagne for the party that afternoon after visiting Snowden, Ann had taken the dagger from Coletti's pocket and had put hyoscine in Muriel's coffee before killing her when she put her to bed. With the case solved, Holt summons Marshall, Ann and Tom. When Marshall announces that the district attorney informed him that Coletti has confessed to both murders, Holt decides to forgo accusing Ann and instead surprises all with an announcement that he and Jane will be married the following day. On his honeymoon cruise, Holt receives word from Marshall that all along he had been protecting Ann, who passed away the previous night. As Holt and Jane resume their honeymoon, Jeff calls to them from a lifeboat.