Arun slumped down on the sofa pushed up against the wall, head bowed as if it were too heavy to lift up. “It’s not that.” He let out a sigh that misted his respirator for a moment. “I’ve got an antidote.”

Victor fell to his knees in front of Arun, not giving a thought to his tailored pants. He took Arun by a shoulder, so tightly Victor’s knuckles went white. Arun didn’t even seem to register Victor’s iron grip. “You have an antidote for this?” Victor spoke slow and deliberate. “And you haven’t given it to them?”

“I can’t!” Arun cried. “It’s my newest batch. And the last time . . .” He punched a fist into his thigh. “Zhou, you saw what can happen. The lab monkeys hemorrhaged to death. I can’t risk that on Lingyi and Iris!”

“But you’ve developed a newer antidote, right?” I asked.

Arun nodded, eyes wide and solemn. “This latest batch hasn’t been tested yet.”

“So test it!” I said.

“The monkeys won’t arrive for two more days,” Arun replied. “And even then, I’d have to infect them with the flu virus first. From everything I’ve gathered on the undernet, this super avian flu hits heavy and fast. We don’t have time.”

One glance at the deathly pale faces of the girls, and I knew he was right.

“They have an eighty percent chance of dying from this, Arun,” Victor said. “Don’t you think it’s worth the risk?”

“If they died from my antidote—,” Arun said.

“They’ll probably die anyway if you aren’t willing to help,” Victor cut him off, sounding furious. “I’ll inject them myself if I have to. I know you brought the antidote; I can see it in your face.” He jumped to his feet and stalked over to Arun’s open backpack.

“All right!” Arun rose, following. “I’ll do it.”

Victor stepped out of the way, and Arun retrieved a long case, pulling two syringes from it. “I’ll do it,” he said again, barely audible this time.

“I agree with Victor,” I said. “You said yourself you were so close.”

Arun shook his head. “ ‘So close’ is not good enough in science. ‘So close’ is not what you inject into your friends. But you’re right: It’s worth the risk if you look at it from a statistical vantage point.”

I almost smiled, because this was so Arun. I was certain he didn’t agree to use the antidote because of our emotional pleas. Arun had agreed because he had done the mathematical probability in his head.