Mansun Wong (Lau Ching Wan), a successful stockbroker brought in by a shady high level syndicate to handle their portfolio, is injured in a car accident while trying to evade mysterious surveillance operative Joe (Daniel Wu), who has been watching and listening in on his every move. The police, led by Inspector Jack Ho (Louis Koo), begin searching for the rogue eavesdropper, but even as Joe causes increasing amounts of collateral damage to evade capture, Ho begins to suspect that Wong, with his connection to the mysterious financial conglomerate the Landlord Club might be the bigger crook. The fate of these three men soon intertwines in a cat-and-mouse game that may bring down the entire stock market.