- Laura James: It's strange. One of you is the man I married, and the other... the man I love - and you should both be one.
- Control Voice: Since the first day that Man stared up at the stars and saw other worlds, there has been no more haunting question than this: What will we find there? Will there be other creatures and will they be like us or, when that ancient dreams comes true, will it turn into a nightmare? Will we find on some distant, frozen planet an alien life of unimaginable horror?
- Henderson James: [admonishing the gardener] You're not supposed to think! You're supposed to obey my orders.
- [epilogue]
- Control Voice: In all the universe, can there be creatures more strange than the species called Man? He creates and destroys, he fumbles and makes mistakes, but the thing that distinguishes him is his ability to learn from his mistakes.
- Henderson James: How long... how long are duplicates permitted to live? S'pose one is created ats, say at, uh, 7:00?
- Miss Thorsen: Midnight, whether its mission has been completed or not. It can be programmed to return to its original in less time, but in any case it must be destroyed within five hours
- Henderson James: The reaon, as I understand it, is the possibility of the duplicate becoming too aware of... of what he is.
- Miss Thorsen: Reconstitution of memory. Contacts, association, stimuli - every experience triggers more memories.
- Henderson James: And the more people he talks to, the more... aware he, uh... becomes.
- Miss Thorsen: Exactly. In time the memory would be fully reestablished as in the original. He becomes human, and aware. Conditions then become chaotic. There have been several cases where it was not the duplicate who was destroyed.
- The Guide: Our next visitor from another planet is the Megasoid. It is the highest form of life ever discovered in space. It has been said the Megasoid, despite its physique, is farther along the evolution scale than Man, and has demonstrably proved its superior intelligence. It communicates and has no trouble learning Earthly languages; however, it is a creature with one all-consuming impulse: to kill. For this reason, the last living specimen was destroyed in the late 1980s.
- [the duplicate man awakens]
- Henderson James: [going over its mission] He is telepathic, has a lightning mind. A Megasoid has no compunction about killing. I must not let it talk to me. I must not talk to it.
- Laura James: [walking in on Henderson and his duplicate] I almost guessed. It simply wasn't possible for one man to have two personalities - or I should say for two men to have one personality, but even that isn't quite right, is it?