In 1905, revolutionist Sun Yat-Sen visits Hong Kong to discuss plans with Tongmenghui members to overthrow the Qing dynasty. But when they find out that assassins have been sent to kill him, they assemble a group of protectors to prevent any attacks.

The film opens in a 19th century river town under lockdown by government troops. Word has reached the emperor that a band of rebels have hidden their families, including the leader’s son Erh Mao, in the town. Rebel supporters are spiriting the children to a boat that will take them to safety.