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 next to an Irish bar, The Banshee. Penny Blake, the young wife of San Francisco’s mayor, finds herself in a bind while visiting the wharf with her Chinese manservant, Jacob. Ah Sahm pays a steep price for playing the hero. The Long Zii clean up a mess, and brace for more bloodshed.

Leary pressures gentleman industrialist Byron Mercer, who is Penny’s father, to hire his men for a cable-car track job — despite the fact that Mayor Blake hasn’t yet awarded Mercer the contract. 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. Buckley urges Mai Ling to eschew restraint and start a war with the Hop Wei.

Chinatown gathers to witness a “prize fight” between elite warriors from the Hop Wei and Long Zii. Buckley plays a bluff in hopes of getting Mercer to lower his fee. Ah Sahm remembers his roots as a fighter, as Ah Toy warns him of the dangers that await. Bill and Lee question Wang Chao about the recent series of sword killings in San Francisco.

Ah Sahm rejects his warrior roots and retreats into the netherworld of the Chinese working class. A guilty Big Bill stands vigil for Lee at the hospital. With the police roughing up tong members in retaliation for their violence, Zing and the Fung Hai make a show of force to compel Mai Ling to honor her partnership. Burned by Buckley, Leary decides to take matters into his own hands at Mercer's factory. Seeking to snap Ah Sahm out of his funk, Chao shares a harrowing story of personal hardship. Ah Toy preaches a not-so-ancient message to Ah Sahm: In the middle of chaos lies opportunity. Season One Finale.

As the police prepare for retribution, Chao comes to Bill with a mutually beneficial proposal. A sympathetic Sophie offers Leary a new plan. Ah Sahm and Penny have a moment when he confides his plans for the future. Buckley urges Blake to take a stand against the Chinese, Lee seeks to ease his pain, Mai Ling invests in a legitimate business, and Nellie urges Ah Toy to imagine a different kind of life for her sex workers.

A guilty Mai Ling tries to make things right with Ah Sahm, who’s more intent than ever on seeking revenge. Penny finds her business in trouble and learns that Ah Sahm has been using her. Leary gets a warning and offers one of his own. Ah Toy pays an emotional visit to Nellie’s Sonoma winery. Bill and Chao put their plot against the Fung Hai into action.

Ah Sahm makes a bold sacrifice to protect Yan Mi, Mai Ling reckons with the consequences of her actions, and Leary reaches his breaking point.

As the Secret Service finally corners the Tongs' printing operation, Ah Sahm must choose between his brothers in the Hop Wei and a future with Yan Mi.