Semi-successful lawyer John Malone is intrigued by local night club singer Anna Marie St. Clair. After meeting her at the club, he is present when her boss (and more?) is killed, and she is arrested for the crime. Sentenced to death, Malone and his faithful secretary set out to find the real murderer, who is probably also responsible for a protection racket Malone is investigating.

After being hired by eccentric dowager Hattie Hatfield to investigate the protection racketeers who have been threatening her local delicatessen owner, brash attorney John J. Malone pays his nightly visit to the Casino Club, where he has become an ardent admirer of the sultry singer Anna Marie St. Claire. When Anna Marie is arrested for the arranged murder of her lover, gangster Big Jim Childers, Malone offers to represent her, but she instead chooses Jessie Conway to be her lawyer. As Anna Marie goes to trial, Joe "Angel" Di Angelo, the operator of a bar and funeral parlor, asks Malone's help in fending off some hoodlums who are demanding protection money, and Malone offers to temporarily buy the bar so that he can deal with them. After Anna Marie is found guilty and sentenced to die, District Attorney Logan summons Malone to hear a deathbed confession from Malloy, the man who actually shot Childers. Malloy is about to divulge the name of the person who employed him to kill Childers, but dies first. After Anna Marie's execution, Malone holds a wake at Angel's club. As Malone expounds upon his theory of ghosts, Anna Marie appears at the window, terrifying the customers. Disappearing through a back door, Malone then climbs into a car bearing Anna Marie and Logan. Anna Marie, whose sentence has been commuted, is furious at the reports of her execution until Malone explains that whoever hired Malloy framed her for murder and consequently, her life is in danger. After Anna Marie agrees to cooperate by pretending to be a ghost, Malone stashes her at Hattie's house. Upon returning to Angel's bar, Malone is confronted by some racketeers demanding protection money. When Malone refuses to pay, the hoodlums methodically dismantle the bar and beat up both Malone and Angel. The next day, Eddie Britt, the owner of the Casino Club, phones Malone to inquire about the "haunting" at Angel's bar. When Anna Marie, heavily veiled and disguised as Hattie, appears at the office, Marguerite "Maggie" Seaton, Malone's secretary who carries a torch for her boss, faints. Next, Mrs. Childers, Big Jim's wife, visits Malone, proclaims her belief in Anna Marie's innocence and offers to locate the departed woman's relatives. Inspector Von Flanagan, Malone's next visitor, answers the phone in the office and hears a man pleading for Malone's help in saving his life. That night, Malone takes Anna Marie to her apartment to pick up some clothes. As she explains that Childers maintained an apartment identical to hers on the floor above, she switches on the lights and finds Conway's body lying dead on the floor. Malone then realizes that Conway must have been his caller earlier that afternoon. Soon after, an intruder wearing a tan overcoat ascends the stairs to search Childer's apartment. After the intruder flees, Malone discovers that the apartment has been ransacked, but Anna Marie calmly states that Childers concealed all his important papers in a secret compartment inside her closet door. Malone notifies the police about Conway's body, but upon returning to Angel's bar, he learns that the body has disappeared. While at Angel's funeral parlor to collect some flowers for Anna Marie's birthday, Malone discovers Conway reposing in a coffin. Realizing that the racketeers planted Conway's body as part of their extortion scheme, Malone instructs Angel to set up a meeting between Rico Di Angelo, his partner and brother, and the mobsters. At the meeting, Angel and Malone overpower the hoodlums and take them to the funeral parlor. As Malone and Angel threaten the racketeers with embalming unless they reveal who hired Malloy, Anna Marie excuses herself to return Hattie's car. After she leaves, a hand slips a live bomb into the room and it explodes, freeing the hoodlums. Soon after, Millie Dale, Anna Marie's successor at the Casino Club, visits Malone in hysterics, claiming that Anna Marie threatened to murder her. When Malone asks about the motive, Millie replies that Anna Marie was jealous of a certain man's attentions to Millie. Just as Millie is about to reveal the name of the man, a gun shot rings out and Millie falls dead to the floor. Later, Malone realizes that Childers' apartment, being identical to Anna Marie's, must contain that same concealed compartment, and there he finds Childers' diary. That night, Malone invites Maggie, Mrs. Childers, Logan and Britt to join him for dinner at the Casino Club. When Anna Marie appears to sing her signature song, Britt stands and fires a gun at her, and in the ensuing chaos, she disappears. Later that evening, Anna Marie comes to Malone's office. After showing her Childers' diary, Malone discloses that he knows that she was Childers' partner in the protection racket while also carrying on a clandestine affair with Britt. Britt, who had fallen in love with Mrs. Childers, decided to eliminate both his rival and Anna Marie by hiring Malloy to kill Childers, then framing Anna Marie for murder. When Malone advises Anna Marie to leave town, she offers to make him her partner instead, but he refuses. After Anna Marie leaves the office, Malone watches from the window as she steps into the street and is arrested by Von Flanagan. Malone then turns and kisses Maggie.