“But what you have now is still a cure,” said Kira. “It still works. Where we come from in New York, we haven’t had an infant live past three days since the Break. We found a way to cure one child a few months ago, but that’s it. We have one miracle child, but you have hundreds. We’ve been trying to reproduce our cure and we can’t do it, but you could give us a future. Please—I’m a medic, I’ve trained for this exact moment my entire life. Take me to your lab, show me how you do it, and we could save tens of thousands of children. An entire generation.” Kira felt herself crying. “We could have a future again.”

“The cure isn’t portable,” said Vale.

“What?” She furrowed her brow in confusion. “How could it not be portable?”

“You’ll see,” said Vale.

Kira stood up. “Right now.”

“Be patient,” he said, waving her back to her chair. She didn’t sit down. “I want to help, but we have to be careful..”

“What is there to be careful about?”

“We have a delicate balance here in the Preserve,” he said. “I’ll help you, but I need to do it without upsetting that balance.”

“Then let us help you,” said Kira eagerly. “I’ve studied RM, we’ve crossed the wasteland, we know the terrain and the politics and everything else. What do you need to know?”

“Nothing tonight,” said Vale. “I’ll talk to you tomorrow.”

Kira clenched her fists in frustration. “What about the expiration date?” she asked. He looked up, eyes wide and curious, as if he didn’t understand. “The Partial expiration date,” she said again, “the mechanism in their genome that kills them after twenty years. Do you know anything about it? Have you figured out how it works?”

“The others will find you a place to stay,” said Vale, rising from his chair and walking to the door. His voice was less certain now, his joy at discussing the microbes replaced with a mumbling uncertainty. “It’s going to rain tonight, and microbes or not, you don’t want to be caught outside.”

“Why won’t you answer me?” Kira demanded.

“I’ll answer you tomorrow,” he said. “Follow Calix, and I’ll send for you in the morning.” He opened the door and gestured toward the hallway.

“First thing in the morning,” said Kira. “Promise us.” Samm stood to follow her.

“Of course,” said Vale. “First thing.”

Calix had been sitting on the floor in the hallway, and rose quickly to her feet. “We need to hurry,” she said. “The acid rains are coming soon; everyone else will be inside.” She looked at Samm. “You can stay at my place—both of you—but we’ll have to hurry.”