Wet-behind-the-ears new recruit Piggy (Kate Tsui) is plunged at the deep end in her first surveillance assignment working alongside her mentor, Sergeant Wong (Simon Yam).

Fatman (Lam Suet) is identified and tracked without his knowledge through a combination of tails, surveillance footage, and data-mining, including accessing his Octopus card.

In the raid on the hideout, Hollow Man flees down a dock and wounds himself mortally in the neck running past a hanging hook, and the other robbers are captured.

The film received generally favourable reception and was hailed for the plot's authentic and dark atmosphere, and realistic use of surveillance tech to make the story believable.

A South Korean remake titled Cold Eyes starring Sul Kyung-gu, Jung Woo-sung and Han Hyo-joo was released in 2013.