"Nothing. How could I? I heard Cameron shouting, other noise. But I couldn't see a thing that wasn't directly overhead, and there wasn't anything."
"I thought so. A geepee could have got in without anyone seeing him. I didn't count them but I was certain all of them had dropped outside. I was mistaken; one of them didn't."
"Why does it have to be a geepee?"
"It just does, Anti. The combustion chamber was retracted while we were all in the control compartment. We didn't do it and therefore it had to be someone back here.
"No man is strong enough to retract the cap, but if he somehow exerted superhuman effort, as soon as the chamber cleared the tubes rocket action would cease and the air in the compartment would exhaust into space."
"So we have a dead geepee in the rocket compartment."
"A geepee doesn't die or even become inactive. Lack of air doesn't hinder it in the least. Not only that, a geepee might be able to escape from the compartment. It's strong and fast enough to open the door against the pressure and get out and close it again in less than a second. We wouldn't notice it because the ship would automatically replenish the small amount of air that would escape."
Anti settled down grimly. "Then there's a geepee on the loose, intent on wrecking us?"
"I'm afraid so."
"Then what are we standing around for? All we have to do is go back to the controls and pick up the robot on the radio. We'll make it go in there and repair the damage it's done."