"Yes, I understand you."

"It is an order. Think about it. I control you now. Isn't that so?"

My heart sank. Whatever the mysterious science involved in my dealing with this mechanism, I was not operating it correctly. The Robot did not move. Finally it said:

"No one—nothing—controls me. I have an independent impulse of my own. The girl must stay here until we return."

Mary gave a faint cry and sank back to the couch, a huddled white heap in her satin dress. I thought she had fainted, but she raised her face to me and tried to smile.

"But I won't leave her, Migul."

"She must stay."

"But why? If you are human now, you must act with a reason."

"Then because, if we fail to kill Tugh, I would not have him confront me with the knowledge I have released this girl. He would derange me; end me."

"I will stay," said Mary faintly. "You go, George. But come back to me."