The Earth, scorched and tarnished, can no longer sustain life. Geodesic domes protect food plants and produce desperately needed oxygen, while children don breathing tanks for the ride to school. Archer Larson, a bitter, lonely teenager with the legacy of unethical experiments implanted in his body, finds himself drawn from his antisocial funk when a new student joins his class. Something is familiar about her. Why does he feel they've met before?
Trying to forget the déjà vu slowly overtaking him—as old prophecies of ruin start to sound like memories and the names of people he's never met start ringing bells—Archer sets aside his disinterest in his classmates. He makes a couple of new friends and reconnects with an old one.
But eventually, he realizes what he has to do and disappears back into the most dangerous moment in all of time: the apocalypse. After all, he knows now that if he doesn't go, the people he's coming to care about will never be born. It will be a struggle to survive—if he survives at all. But the young man with the bruised and traumatized heart has something to care about now.
Meanwhile, left behind in their own time, Archer's new and old friends try to get to grips with the strange things going on in their school, and face the growing suspicion that there's a plan behind all of them...
