James Kestner is a government secret agent on the trail of a band of counterfeiters and particularly anxious to locate the head of the gang, Frank Lambert, who, in addition to his skill as a counterfeiter, is known to the underworld as the only man who can fill in the perforations of a used bank check. Kestner locates the band in their underground work shop near the river front. He cleverly maneuvers his way into the headquarters of the band when it is empty, but is caught in the act of searching for incriminating evidence by "Bull's Eye" Cherry, a clever girl crook, and one of the mainstays of Lambert's crowd. Lambert and his daughter, who has been educated in crime by her father, return to find Kestner held at the point of Cherry's revolver. Lambert is for killing the detective outright. Impressed by Kestner's brave demeanor, Maura intercedes in his behalf, but finding her father determined in his intention to kill the government agent, she pretends that the police are outside.