A detective’s wife joins his work and uses unusual methods to work on a murder case he is also investigating.
Sally Reardon (Joan Blondell) goes to her husband’s detective office and hears a woman crying because William Reardon (Melvyn Douglas) cannot keep her any more. Sally is relieved to learn she is his secretary and says she will be his secretary. He says he was making $3,500 a year working for the district attorney. Now he has no business. She says he needs publicity to get clients. A man knocks, and she is happy and types. The man leaves, and Bill shows her the bill for $375 due for three months rent. He calls the D. A. so that he can get his old job back. She says she will carry on there. He leaves and tells her to start packing. Lola Fraser (Mary Astor) walks in and is about to leave; but Sally knows her name and tells her she is a detective. Lola wants Anne Calhoun followed. She had been engaged to her husband. Lola asks for a complete report and gives her $300 in advance. She asks her to come to the Skyline Club tonight to see this woman.
Bill calls Sally and says he will get $75 every week. She persuades him to take her to the Skyline Club to celebrate.
At the Skyline Club Bill tries to stop Sally from ordering a la carte and does not let her order wine. They have each had three martinis, and he says he has only $20 on him. He sees Nick Shane (Jerome Cowan) and gets $50 from him by writing a check. Shane gets the D. A.’s home phone number from him. Bill tells Sally that Nick is a gambler. Sally chooses a table in the middle so she can see people. She sees Lola come in with her husband Walter Fraser, Anne Calhoun (Frances Drake), and her fiancé Jerry Marlowe (Robert Paige). Sally contrives to get a table near them by complaining about a waiter. Bill criticizes her and asks her to dance. She declines to dance with him because of his age. Anne wants to dance and tells Jerry she promised to dance with Walter. Sally sees them and asks Bill to dance. Anne asks Walter if he brought it. Sally moves near them. Walter hands a paper to Anne. Sally follows Anne into the ladies room while Bill orders champagne. Anne passes the paper to Shane. Sally wants champagne too. Jerry is angry and threatens to kill anyone who gets between him and Anne. Sally falls backwards in her chair. Bill says she has been snooping. Bill shakes hands with a divorce lawyer and decides to talk to him.
Much later Bill and Sally are drunk in the deserted club. He tells her the grounds for divorce.
They come home drunk, and he goes right to bed. She suggests hot milk and takes off his collar.
Sally wakes up to an alarm and finds Bill asleep on the floor. She gets the newspaper and learns that Walter was murdered in Jerry’s penthouse. She remembers the threat that Jerry made. She calls a newspaper and tells the editor that she knows who killed Walter.
At home she answers questions of a reporter while a photographer takes pictures. She says Jerry threatened Walter. Bill has his picture taken without his pants. Sally tries to get the plate, and they run out. She hides the newspaper and tells Bill he has to go to work. She says no picture could ever come between them. He answers the phone and tells her that Fraser was murdered. He rushes out, and she laughs.
The District Attorney (Thurston Hall) shows Bill a newspaper with pictures of him and Sally.
Jerry admits to his lawyer Ketterling (Pierre Watkin) that he made the threat. Sally comes in and talks with the lawyer, who has hired her. She fixes the threat story by calling the newspaper and telling them that Marlowe is innocent.
Sally comes home and finds Bill reading the newspaper. He complains about the picture. She backs up and mollifies him with kisses. She promises to make it up to him. She advises him to question the butler. He says he and the D. A. are going to re-enact the crime.
At Marlowe’s penthouse Bill and the D. A. look around. Lola comes in. A policeman keeps Sally from entering and takes in a note from her to Bill. Inside Bill is questioning Anne and Lola. Lola says she was in the library. Marlowe is not sure where he was. Anne says Jerry was in the kitchen with her. Lola says Jerry walked into the living-room with her. Bill is given the note about the butler. Bill questions him, and Jerry interrupts. Anne tells Lola that Jerry is innocent. Bill looks for the gun and finds it in the freezer. He washes and dries it and hands it to the policeman to have it checked for finger-prints. Bill hands his gun to the butler who says he does not use guns. Bill asks how he knew how to release the safety. The D.A. tells Anne to stay in town. Sally has been watching from above.
Bill, the D. A. and two policemen are interrogating the butler. Bill says the pawnbroker who sold the gun identified him. The butler says Marlowe paid him to buy the gun, and then the gun was missing. The butler says he heard the shot, came down, and hid the gun. Marlowe says that Anne was writing letters to Fraser.
Sally and Shane meet while waiting to see the D. A., who comes out and tells Shane to come back another time. Sally tells the D. A. she has new clues. She says Shane is mixed up in the case. The D. A. says he was talking to Shane on the phone when the murder was committed.
Sally goes home and puts two boxes under a bed. She calls Ketterling that it is bad for Marlowe. She tells him she has a plan but does not know what it is. She opens the closet, and Bill falls on the floor. He admits he heard her phone call. She says police are listening to their calls. He says he knows Ketterling and Marlowe hired her. She says she has clients, but he says he may be a murderer. She says he is not. They make a bet who will solve the case. He says his men will shadow her. He kisses her and goes out.
A woman dressed in mourning comes into the Fraser house, and it is Sally. A man with a gun threatens her, and it is Bill. She says she was scared. He is going through papers, and she helps. The phone rings, but they do not answer.
Anne leaves the phone booth.
Sally uses some of Lola’s expensive perfume. She tries to open a safe but starts music instead. They hear a key and hide. Anne comes in and looks in the desk papers. Bill speaks to her, and she takes out a gun. Bill grabs the gun while Sally takes the paper and runs out. Bill asks Anne to tell him about it. He says she blackmailed Fraser and then killed him. She says she was desperate because she lost $2,000 at roulette. She did not want Jerry to find out. She says Jerry did not kill him because Lola did out of jealousy. Bill asks if she has a gun permit and says he can arrest her.
Bill comes home and tells Sally he has a search warrant. Two policemen begin searching. Bill rips up a photo of himself. Detective Flannigan says he is looking for a letter. Sally says when he is warm or cold. She picks up the phone and finds no one is there. She calls Lola to make an appointment.
Lola tells Shane it is the dumb Reardon woman. She learns Sally has a letter, and they agree to meet at nine.
Bill pushes Sally off the bed. He says he will search her, and they go in the bathroom. He tells her to take her clothes off as the police listen.
Shane asks Lola when he is getting the fifty grand. The police are listening to their conversation. They both say the police may suspect the other. Shane pretends to leave and hides in a closet. Lola answers the door, and Sally comes in. Sally shows her the letter. Lola rips it up. Sally says she will find a new clue. Sally finds a dictaphone and insults Bill and the D. A. Lola wonders how long it has been there. Lola tells Sally she heard someone on the phone line just before the murder. Sally mentions the butler. Lola says he was talking to the D. A. about gambling. Sally says it was Shane. He comes out of the closet, but then Bill comes in and arrests Lola and Sally.
At the police station Bill questions Lola, who says she could not pay money she owed Shane. She admits that Shane was her boyfriend before she married Walter. The D. A. says she can go, and she leaves. Bill says Marlowe was jealous. The detective questions Sally, who says she cannot betray Lola’s confidence. Bill comes in and says they are wasting their time. The detective Flannigan continues to question her. In the morning Bill tells her it is serious. He advises her to work with the police. She says Lola told her that Shane was talking to the D. A. on the phone. Bill tells the D. A. that Shane used that as an alibi. The D. A. says his wife said that. Bill says it could be true.
Bill and police with guns enter an apartment, and he tells the police to look for Shane. A call is put out to arrest him for murder. The D. A. learns that Sally got out of jail.
Sally comes home and smells perfume. She looks in the closet, and a body falls out. She picks up a knife. A shot is heard, and she falls. Flannigan and a policeman come in, and Flannigan says it is Shane.
Bill unlocks doors. Bill finds the place where Shane called the D. A.
Sally goes in the bathroom and runs water and then climbs out the window and down a ladder. On the street she gets a ride from a policeman who likes her.
Bill calls the D. A.’s private line and says he knows who hired Shane. The D. A. says Shane was killed in Bill’s apartment, and the police have Sally there.
Sally goes to see Lola and pushes her way in. Lola says she is busy. Sally complains that her client committed murder; Shane is dead. Lola admits she hated and feared him. She denies she killed him. Sally says she found the letter by the body. Lola admits she did kill him. Sally says they can plead insanity.
The police get a call to be on the lookout for Sally Reardon for suspicion of murder. The D. A. and Bill go in a police car.
Sally has just called the newspapers with the story. Bill comes in, and she explains the case and shows him Lola’s confession. Bill says Lola offered Shane $50,000 to kill her husband. Sally explains how she got Lola to confess. Photographers come in and take pictures of Sally. The D. A. tells them what happened. Sally says she will get $500 for the inside story. She tells Bill she would not give them the “real inside dope.”
This comedy uses a murder mystery as a plot but entertains with the witty remarks by the married detectives who have a competitive relationship.