The fever passed; control of his body returned.
"For you?" Hertha asked.
He half propped himself up on the cot. He waved his hand weakly. "Those dead plants. You must throw them out and bring in more."
He listened tensely, imagining that he could hear the precious oxygen hiss in from the emergency tank to freshen and revitalize the dead air. Halfway down on the dial. Not enough for ten days, even for one person, unless the air was replenished by bringing in plants.
"Hertha, we've got to purify this air. Now listen. Listen carefully, Hertha. You've seen me dig up those plants on the outside?"
"Yes, I watch when you go out. I always watch, Jimmy."
"Good. You've got to do the same thing. You've got to go out and dig up some plants. You've got to bring them in here and plant them the way I did. You know which ones they are?"
"Yes," she said.
He closed his eyes, trying to think of a way to make her see how vital a thing a tiny plant could be. The complex chemistry of it bubbled to the surface of his mind. He wanted to tell her why the plants died in the artificial human atmosphere and had to be replaced every week or so. He wanted to tell her, but he was growing weaker.
"They purify the air by releasing oxygen. You understand?"