From two New York Times–bestselling authors, a group of talented young people heads to the International Space Station for a new mission: saving Earth from invasion . . . Now that JJ Wren, her brother Dylan, and friends King and Song-Ye have seen Earth''s dark future—facing an invasion by the hideous alien Kylarn—they know they have to prepare the human race. At the local Challenger Center, the mysterious Commander Zota sends JJ and her friends off on another mission, this time to the International Space Station Complex, where they meet old friends, survivors from the disaster at Moonbase Magellan, as well as a mysterious girl, Mira, who claims to be from the past. Another Star Challenger with her own mentor, just like Commander Zota. Together, they have to discover and stop the continuing plans of the alien invaders. And the Kylarn have set their sights on conquering, or destroying, the space station, so that Earth has no protection at all! "The Star Challengers books inspire young readers with [a] sense of adventure, introducing them to a universe of exciting possibilities." —Buzz Aldrin "[There''s] never a dull moment in these fast-paced books . . . Don''t miss this thought-provoking series." —Lurlene McDaniel, author of Breathless