The Gray Raid: The Explorer Book 2 - The Explorer, #2

The sequel to the YA Sci-Fi novel, The Blue Barricade, has arrived!It's been a month since that fateful day on New Earth, also known as Mars. The day when Red City found itself under attack by the shadowy organization known as the Oppressed. Despite surviving the ordeal, Wander Locke finds himself on the one planet in the galaxy that was meant to be uninhabitable: Earth. Stranded with his best friend, Laura Genki, and his mentor, Theodore Manning, the three must cooperate with the very forces keeping them there if they are to have any hope of retrieving what they lost, and returning home safe and sound.