A smooth, smart distillation of sci-fi staples, beginning when Roy and Barney go to investigate a UFO on their street and ""a ramp came out like a tongue,"" luring them in. When they enter, the UFO takes off. ""'We've been kidnapped!' Roy said. Barney shook his head. 'Not really. We weren't forced. There's no one here but us.'"" But then two strange creatures do appear, demanding an unspecified ""it""--which turns out to be a gem of power lost by their leader on the strange pink planet where the ship soon lands. There's a threat, a chase, a mutiny, a scramble for the gem, and at last a fast trip home, with the gem (now in the boys' possession) to guide the way. It works, because Robinson neither takes it seriously nor tries for belly laughs.