John "Dutch" Malone, the leader of a powerful waterfront gang, orders his right-hand man, Anjo Ferranti, to kill nautical supply company owner Rodgers in an effort to take over his company. After carrying out his mission, Anjo is warned by Malone, who is leaving on a hunting trip, not to get too ambitious while he is away. Malone, an avid hunter, also tells Anjo to visit taxidermist Peter Winkly for a surprise. On his way to the country, however, Malone is seriously injured in an automobile wreck. When police commissioner Hogan and District Attorney Brady learn of the accident, they contact Winkly, who had informed them of his uncanny resemblance to Malone after they first met. Winkly, whose younger brother was an innocent victim of a street gunfight between Malone's men and their rivals, is eager to help Hogan and Brady find enough evidence to convict Malone of several murders. With Malone in the hospital, Hogan and Brady bring in several experts to teach Winkly how to impersonate the gangster. They also plant a newspaper story that Malone had not been seriously injured, and two weeks later, Winkly completes his training and goes to Malone's apartment. Malone's girl friend Rita is annoyed by Winkly's lack of attention to her, but Winkly bullies Anjo enough to allay his suspicions. Determined to obtain evidence against all the gangs, Winkly orders his men to stir up trouble between the rival gang bosses. Meanwhile, Rodgers daughter Jane has taken over the business and refuses Anjo's attempts to collect protection money. Curious about Jane's claims that she has information that could implicate Malone in her father's death, Winkly meets with her and makes a date with her for that evening. Jane fights her attraction to Winkly, who in his guise as Malone orders her to turn over her evidence "or else." She leaves the club where they are talking in order to meet with fellow businessman J. M. Meyer, who claims to have evidence against Malone. Jane is preceded to Meyer's office by Winkly, who had been warned that Ortega, one of Malone's gunmen, was on his way to kill Meyer. Winkly succeeds in killing Ortega before he shoots Meyer, but must conceal his action from Jane in order to prevent her from wondering why "Malone" would kill one of his own men. Jane does discover that Meyer is alive, however, but is kidnapped by Anjo before she can confront Winkly. After Winkly sets up a meeting with the rival gang leaders, who agree to bring him all of their written records, he learns that Jane is being held captive. With the aid of Dan, Jane's foreman, Winkly frees Jane, but in the process Anjo discovers Winkly's true identity. Meanwhile, Malone has escaped from the hospital and learns from Rita that Winkly is meeting with the other gangs that night. Malone breaks into the meeting just as Winkly gets the records, and during the ensuing shootout, in which Hogan, Brady and their men, participate, Anjo shoots Malone and is in turn shot by a policeman. Winkly gives the records to Hogan, and soon after, the waterfront is free of all gang activity. With his job completed, Winkly returns to his taxidermy shop and pursues a romance with Jane.