Inspector Waipong Wong has to put his life and resignation from the HKPD on hold to investigate his former partner's mysterious murder. What he and his crack team of three other cops uncover is a plot far more sinister than they originally anticipated.

In 1937 Shanghai, a soldier and a young woman have an awkward meet-cute in darkness under a bridge as they seek refuge during a bomb raid. Ten years later, the soldier, now a burgeoning songwriter and tuba-player in a marching band, is back in town desperately searching for his would-be soulmate. As fate would have it they end up living in the same building unbeknownst to each other. Through a series of mishaps, he mistakes her new ingénue roommate for his love interest and wacky love triangle hijinks ensue.

A group of Hong Kong criminals are hired to rescue student protesters fleeing mainland China. Caught in a political tug-of-war, they must evade ruthless mainland authorities pursuing them at every turn.