Astro visits the underground uranium quarry on Cross Island with Dr. Elephant and meets Buck, an incomplete robot. Professor Terapin, Buck's creator, breaks out of prison with Mandrake's gang, sneaks onto the island and makes Buck into a transformation robot, but Terapin's gang have other, darker plans for Buck.Astro visits the underground uranium quarry on Cross Island with Dr. Elephant and meets Buck, an incomplete robot. Professor Terapin, Buck's creator, breaks out of prison with Mandrake's gang, sneaks onto the island and makes Buck into a transformation robot, but Terapin's gang have other, darker plans for Buck.