 The crew of the Liberator head to the planet Aristo to deliver medical supplies to the computer scientist Ensor, creator of the mobile super-computer Orac. Where Blake and Cally require from Ensor, anti-radiation drugs for Avon, Gan, Vila and Jenna who have absorbed radiation from Cephlon. Travis and Serverlan have also arrived on Aristo as they bid on claiming Orac for themselves.