Plenty of teenagers would kill for a chance to leave Earth behind and journey to Mars. But for Cal, that situation is pretty much reversed. One of only seven people ever born on the Red Planet, Cal dreams of returning to the homeland of his parents where, despite its many flaws, he can be free to live life his way. But Cal’s plan of getting back to Earth may have to be put on hold, as an unknown presence threatens the very existence of the boy, his family and everyone who now calls Mars their home.