It has been over 2 years since the agressive Orbs attacked the Earth. Now you work as a Manhunter, the highest post which can a human achieve in the Orb Aliance. Your job is to hunt down all humans who, in some way, have wronged the Aliance. Once you capture them, the Aliance will correct them.
The story continues when you chase the ruthless killer to San Francisco. Hopefully you will be able to somehow damage the Orb Aliance too.