In Gearford, racing is everything.

Every kid dreams of the day they turn thirteen and take the wheel.

Revel Morgan isn't there yet.

But when he discovers a buried monster truck deep in the canyon, everything changes. The truck is called Lava Crusher. The moment Revel gets behind the wheel, there is no turning back.

Suddenly, Revel is pulled into a hidden world beneath the city. A shifting underground racing circuit powered by an ancient force known as the Flame Crystal. A place filled with collapsing tunnels, impossible tracks, and ghostly racers who do not play by the rules.

Because the stories are true.

The Skeleton King is real. And he wants the Crystal.

To stand a chance, Revel must do what he has always dreamed of. He must qualify for the Gearford Grand Prix and race against the best drivers in the city. But every race pulls him deeper into the mystery and closer to a danger that has been waiting for him.

He will not be racing alone. His fearless twin sister Rylie and a wild, unpredictable crew are right there with him. Even that might not be enough.

If he fails, it will not just cost him the finish line.

The whole city is at risk.