It was supposed to be just an educational field trip to the Challenger Learning Center, but JJ Wren and her friends find themselves transported into the future, to a time when the human race is under siege from deadly alien invaders. The evil Kylarn have shifted the orbits of three asteroids, sending them tumbling toward Earth—and a direct impact will have devastating consequences. With instructions and skills they learn from the mysterious Commander Zota, JJ and her fellow Star Challengers embark on a mission to the asteroids before it's too late, hoping to divert the giant rocks before they strike Earth. But the alien invaders aren't the only enemy—the Star Challengers have to worry about human traitors, too!