New York racketeer Lucky Jordan is drafted into the army despite all his underhanded efforts to stay out.  Lucky shirks his duties and spends most of his time in the canteen until Jill Evans, who works at the canteen, reports him as absent without leave and he is thrown into the penitentiary.  When Lucky's lawyer, Ernest Higgins, informs him that he has been unable to get him a desk job, Lucky breaks out of the camp and commandeers a car.  Two thugs cross his path and try to steal the briefcase in the car, but they escape after their struggle with Lucky is interrupted by the arrival of Jill.  Lucky then kidnaps Jill and eventually returns to his office in the city, where he finds that his former underling, Slip Moran, has taken over.  Slip is only interested in the briefcase that Jill tossed out of the car, and reveals that he has made a deal to sell the tank plans contained in the briefcase to the enemy.

Lucky, Slip and Jill return to the country road and find the briefcase.  After Lucky preempts Slip's murder attempt by knocking him out, Jill prevents Lucky from killing Slip.  Later that night, Jill tries to stir up Lucky's patriotism so that he will return the plans to the army, but he is resistant, so she resorts to her feminine wiles to distract him and escapes.  Lucky retains the plans, however, and returns to the city to make a deal with Slip.

Lucky goes into hiding with Annie, an elderly panhandler who had impersonated his mother for the draft board, and who has discovered that she likes being a "mom." Lucky strikes a deal with Slip for the plans, but Slip's thugs track Lucky to Annie's tenement apartment, and while Lucky is gone, they beat Annie in order to find the briefcase.  Lucky returns and comforts Annie, but the thugs still lurk in the apartment and attack him and get the briefcase.  Lucky learns from his former secretary, Pearl, that Slip recently made a deal for a type of tulip called the "Torch of Holland."

Lucky tracks the flower to the private Kilpatrick Gardens on Long Island and sees Slip and Kilpatrick in the greenhouse making arrangements for the plans.  Lucky turns on the sprinklers, grabs the plans and, after a chase, hides them, with instructions to contact the FBI, in the umbrella of a visiting patron.  Jill, who has been following Lucky, captures him in the Kilpatrick house but is shocked when she learns that Kilpatrick is not a patriot, but a German agent named Kesselman.  Lucky is beaten and sends Kilpatrick searching for the plans on his grounds.

While Kilpatrick declares the virtues of the Nazis, Jill distracts the armed gardener and with Lucky, overwhelms their captors.  Just as Lucky, who has announced his intentions to return the plans, is preparing to shoot the criminals, FBI.  agents arrive and arrest everyone, including Lucky.  For his efforts, Lucky is allowed to return to the army and serve his time in the penitentiary.