- Canto of Quasti: Once I was a great warrior and leader of my race, but that was many centuries ago.
- Prof. John Robinson: What is it you want with me?
- Canto of Quasti: My body has long ago been used up. I want... yours as a replacement.
- Canto of Quasti: Go, but remember - I am now a part of you.
- Prof. John Robinson: No. I won't let you.
- Canto of Quasti: There is nothing you can do, and every time you sleep I will gain further control of your mind. You are not to remember anything that has happened here. Now, go, and take good care of our body.
- Will Robinson: If you can help dad, I'm all for it.
- Dr. Zachary Smith: Very well, I shall undertake to start working on my patient at the earliest opportunity.
- The Robot: May I speak?
- Dr. Zachary Smith: You have my permission.
- The Robot: In my opinion, it is not Professor Robinson who needs psychiatric treatment. It is his doctor.
- Dr. Zachary Smith: Just you wait, you deplorable dummy.
- Dr. Zachary Smith: Let me handle the professor. Possibly you're unaware that I'm completely familiar with the latest techniques in the field of psychiatry.
- Maj. Don West: As a doctor or a patient?
- Dr. Zachary Smith: Spare me your insulting barbs, Major, or I shall withdraw my offer of help.
- Canto of Quasti: The mechanical man has told them what is happening. That could be very unfortunate.
- Prof. John Robinson: There's nothing they can do to stop us now.
- Canto of Quasti: Perhaps. Still, they could be a hindrance.
- Prof. John Robinson: Then we must remove them.
- Canto of Quasti: [laughs] We are beginning to think more and more alike.