Ikka doesn't know it yet, but she has spent her entire life in The Race.

Ikka's days are consumed with speeding across the endless desert, competing against the other racers in her colossal eight-wheeled X-Runner. She is focused on the competition, but unsettled in her mind.

Ikka is aware that she can remember only one day at a time, but she doesn't know why. She suspects that other racers are missing their memories too, but they seem blissfully unaware--distracted by the thrill of The Race, and obsessed with rising in the ranks of the competition.

But one night, Ikka witnesses another X-Runner disappear. Its lights vanish on the peak of a mountain, and its heat signal is erased from her navigation system. Someone is trying to pretend this vehicle never existed, and Ikka becomes determined to find out why.

When Ikka abandons her X-Runner, her repressed memories begin to resurface in terrifying fragments. Soon she remembers being held captive, chained in a glass-walled cage. She doesn't know who put her there, or how she ended up in the competition.

Now Ikka is faced with a choice--hide and protect herself, or risk everything to uncover the true purpose of The Race...