Adventure in Space (Legend of Otherland #3)

Description

Young Bunker Charles and his friend Gittel are accidental stowaways on the test flight of Bunker's father's new space ship. They are drawn against their will to the planet Acron, which is run by the mysterious four-eyed graymanoids, who covet the triptonite from which inventor Steven Charles' prototype spaceship is made. He is captured and forced to work to provide them with the formula. Bunker and Gittel escape. Can they overcome the mind control which keeps the planet's kidnapped population enslaved, and free Steven and their new friends?