After Dr I.M. Sinister and his 2 henchmen 'Red' and 'Mouse' escape from Sing Song Prison, they hide at the mining colony of Cross Island disguised as robots. The gang overpowers Dr Elefun, who is repairing the robot miners. As chance has it, one boy robot on the island was built by Dr Sinister. While holding Elefun at gunpoint, Sinister demands not only HIS robot but the use of parts from Astroboy, so he can build a super-robot capable of changing into an array of animals.