In the bleak alternate near future New York of 2025, Ellen, an over-educated, under-employed delivery girl gets pulled into the mob-controlled underworld of illicit SHIFT-racing in the twisted maze of subway tunnels beneath the city.
SHIFT technology allows objects and people to pass through solid matter. In this future where economic and environmental decline has worsened and the gap between rich and poor has never been wider, a single act of defiance against the corrupt protectionist thugs on her street leads down a path to understanding the nature of her city and its true masters. Her experience joyriding in stolen cars as a teenager becomes extremely useful, as she enters a racing league where various conflicting underworld factions recreate the bloody Roman Circus Maximus using high-tech miniaturized aircraft in the tunnels of the city.
In these tight confines and absurd speeds, crashing is just a matter of time, but the mysterious SHIFT technology, repurposed from military stealth aircraft, can land you on the right side of the razor's edge between life and death.