"Master storyteller Hale takes readers to dizzying new heights . . . A can't-miss adventure." --Kiersten White, New York Times bestselling author of And I Darken

In this thrilling sci-fi adventure, New York Times bestselling author Shannon Hale asks the question: How far would you go to save the world?

When Maisie Danger Brown nabbed a spot at a NASA-like summer boot camp, she never expected to uncover a conspiracy that would change her life forever.

And she definitely didn't plan to fall in love.

But now there's no going back--Maisie's the only thing standing between the Earth and annihilation. She must become the hero the world needs. The only problem is: how does a regular girl from Salt Lake City do that, exactly? It's not as though there's a handbook for this sort of thing. It's up to Maisie to come up with a plan--and find the courage to carry it out-before she loses her heart . . . and her life.

Equal parts romance and action-adventure, this explosive story is sure to leave both longtime Shannon Hale fans and avid science fiction readers completely breathless.