It is the middle of the 21st century and Tokyo is expanding and filling the bay with landfill to make room for the bursting population. But suddenly Tokyo suffers one of its greatest earthquakes, and the landfill liquefies, creating untold damage in the newly-made urban area.

The members of Self-Defense Force Rescue Squad Four are attacked and murdered as they are sent to help. They start uncovering the mystery that killed their squad: with their first clue in the south-Shinjuku bar called Chicago.

What they're digging up is a plot of murder and destruction - one that wipes out nearly the entire squad and leaves its two surviving members, the fierce Rei and her cool, handsome partner Uozumi, in a fight for their lives.