The black dove

Cowpokes Gustav "Old Red" Amlingmeyer and his brother Otto, down and out in San Francisco in the summer of 1893, decide to become professional detectives and set out to investigate the death of their friend Dr. Chan, landing them in hot water with crooked police, Barbary Coast hoodlums, and Chinatown tongs, all of whom are looking for the elusive "Black Dove.".