The game takes place in the year 2065 in Hong Kong. The city is suddenly attacked by a hostile force known as the Republic, led by a rogue Chinese general named Yan Lo. An international peacekeeping force stationed in Hong Kong, known as the Liberty Coalition, is tasked with defending the island from the invasion.
The story follows Liberty Coalition 2nd Lieutenant Nathan Frost, who is critically injured in a surprise attack by the Republic while attempting to save the life of a wounded soldier. He is rebuilt by the Coalition using experimental nano-technology. Using the powers granted to him by his nano-technology augmentations, Frost spearheads the Coalition's counter-attack against the Republic, eventually rescuing a defecting Republic scientist named Dr. Joseph Liaw. Dr. Liaw informs Frost about a plot by General Yan Lo known as Project: Snowblind.