San Francisco, 1878: Ah Sahm, a newly arrived Chinese immigrant with serious fighting skills, is introduced by a fixer named Chao to Chinatown's most ruthless tong, the Hop Wei. After impressing Young Jun, son of tong leader Father Jun, Ah Sahm is branded.

Intercepting a shipment of opium at the docks, Young Jun, with Ah Sahm and his Hop Wei lieutenant Bolo in tow, decides to send a message to Long Zii. Big Bill and Lee investigate a grisly murder scene in an alley, and Ah Sahm pays a steep price for playing the hero.

Leary pressures Byron Mercer, Penny's father and a gentleman industrialist, to hire his men for a cable-car track job. Accused of assault and perhaps worse, Ah Sahm gets a cold shoulder from the Hop Wei, with his fate in the hands of an unexpected ally.

Big Bill finds himself compromised by his gambling excesses, but discovers a possible solution after an opium den raid. After meeting with leaders of the Fung Hai tong, Mai Ling offers Ah Sahm a way out of a protracted - and bloody - tong war.

Transporting precious cargo via stagecoach, Ah Sahm and Young Jun are forced to spend the night with three strangers at a frontier saloon in the middle of nowhere. The detour turns perilous when Harlan French, a notorious outlaw, shows up with his henchmen.

Tensions soar between the Hop Wei and Long Zii after an assassination attempt during a boisterous parade. Big Bill sets out to pay his debt to Jack Damon. Mayor Blake and Deputy Mayor Buckley get a mandate from Robert Crestwood, a senator with eyes on the White House.