Attorney Jack Durant, Warner Baxter, wins an acquittal for racketeer Tony Gazotti, Nat Pendleton, on a high-profile murder charge and waives his fee. His staid law firm views this as a stain on their reputation, and when he refuses to abandon this flashy new line of work, they part ways. His upper-class girlfriend Sue Leonard, Martha Sleeper, breaks off their engagement and later agrees to marry Tom Siddall, Phillips Holmes, but only if he gives up his mistress, Mimi Montagne, Mae Clarke. Although Tom offers Mimi a generous settlement, she grows furious.
Mimi quickly returns to her former lover, gangster Jim Crelliman, C. Henry Gordon. He has her arrange for Tom to meet her at a wild party. After they go out on the balcony to talk, a shot is heard; Mimi is dead, and Tom stands with a revolver in his hand. The pawnbroker Levi Levitoff, Carl Stockdale, tells the police that he sold Tom the gun the same day. Sue begs Jack to defend Tom. He agrees, though he receives an anonymous phone call telling him to stay out of it.
Jack asks Tony to dig up information. Tony introduces him to Gertie Waxted, Myrna Loy, Mimi's friend, who says she arrived after the murder but may hold crucial clues. He invites her to spend the night in his suite, and she is surprised when he sleeps on the couch.
The next morning, Sue asks Jack to drop the case because she has received a threat. When Gertie appears in Jack's robe, Sue hastily departs, even though Gertie tells her that Jack is still in love with her.
Jack questions Levitoff without success; Levitoff is murdered. Jack then goes to Gertie's apartment to fetch clothes for her. Crelliman shows up and offers him $200,000 to take a long vacation; Jack refuses, and Crelliman threatens him. Jack returns and discovers that the apartment above Gertie's belongs to Murtoch, one of Crelliman's gunmen, George E. Stone. From Mimi's wounds, he believes the killer shot from a higher position. An elevator operator warns Jim that Crelliman's men are waiting in the lobby and guides him to the service elevator.
Jack spots Gertie in a club with Murtoch and jumps to conclusions, but she explains she needed to move Murtoch so Jack wouldn't stumble across him while breaking in. Apologies follow, and Jack admits he is in love with Gertie. He asks her to marry him, but their moment is interrupted by a call from Tony, who has learned that Crelliman intends to have Murtoch killed. Jack, aided by Police Lieutenant Steve Stevens, Robert Emmett O'Connor, and a small squad, tricks Murtoch into confessing.
Gertie herself lures Crelliman onto the roof of the neighboring building. After Murtoch confesses, Jack sets a trap for the conspirators. Meanwhile, Gertie tells Crelliman that she frightened Jack into accepting the plan, but he doesn't believe her and orders his men to take her "for a ride." Gunfire erupts; Jack and the police rush in to find Crelliman and his henchmen dead. Tony saves Gertie but dies from a gunshot wound in the next room.
With the danger past, Gertie begins to pack, thinking Jack will rekindle his life with Sue. He reveals his intention to marry her and take her to Europe, insisting that she will do until someone more suitable comes along.
