Will returns to camp following a cosmic storm. John and Maureen are not there as they are at the weather relay station for a few nights. When he gets there, the rest of the family are acting strange. HE finds out they are androids, sent to learn how to cope like the Robinsons and teach the rest of their race when they return home. The real Robinsons, are kept in a tube, as they are not allowed to come in to contact with their double. Will must teach them to become like their counterparts. He notices that Dr Smith android is somewhat defective but carries on anyway. He teaches them to pack drilling equipment and cook, and everything that the Robinson's and Don do. However Dr Smith android is exactly like Dr Smith and is lazy. The Androids are sent home, except Dr Smith, and again excluding Dr Smith, the real Penny, Judy and Don are returned. Android Dr Smith realises that Will doesn't love him like he loves the real Dr Smith because he is fake. The Android takes himself back to the cave where Dr Smith is and pushes his master Lemnoc aside. He looks at Dr Smith in the tank and tells him to go back to Will, where he will be loved. He opens the tube, and Dr Smith rushes out past Lemnoc. Lemnoc goes inside and finds a pile of ash, where the Android disintegrated. Dr Smith returns to camp and all are overjoyed that he is returned.