Roxy Doyle is contacted by Allan Pinkerton's son, Robert, of the famed Pinkerton Agency, who requests that she go undercover in San Francisco's Barbary Coast in a place that has come to be known as The Shanghai Saloon. Since she was recommended to Pinkerton by Clint Adams, the Gunsmith, she decides to take the job. She ends up working as a saloon girl, and is on the lookout for a gang who has been shanghaiing men at an alarming rate. When one man is killed rather than taken, the job becomes one that might even threaten her own life. Although she's wearing colorful dresses rather than her normal trail clothes, she's still Lady Gunsmith, and uses both her gun and her feminine wiles to do the job.