Only a week ago Grey Alexander thought she and her sister were orphans. And like everyone else she believed Jupiter was uninhabitable. Now she's standing on its surface, reunited with her mom and dad and on the brink of an interplanetary war. The government of Mazdaar is ruthlessly determined to claim Jupiter like they already have Earth, but Grey has joined her parents and Commander Fleur March in the Yien Dynasty's resistance effort. Jupiter, where extinct animals roam free and seem to have an uncanny ability to communicate with her sister, is the last hope for the freedom of mankind.