On the planet Arsu, Bella Glass steps into a rose garden and is thrown 140 years into the future, crashing into the life and vehicle of Kai Craig. Kai is a man dying by inches, struggling against the last vestiges of a war that has ravaged the planet, his body poisoned by radiation from a bomb that turns men into monsters. As Bella faces a world she doesn't recognize and tries to figure out how to return home, she finds herself falling for Kai's kindness and loyalty. But when they discover that someone has traveled through time to Bella's past intent on changing the outcome of the war, Bella must choose between Kai and preventing a devastating alteration of the timeline. As Bella races to save her planet, she must leave Kai alone just as the effects of the bomb to turn him into a rage-filled beast that threatens everyone close to him. With time running out, Bella and Kai have only one chance to prevent losing a war that's already been won and succeeding might mean that they must give up a love they were never meant to have.