I knew this and I knew these particular risks; it was, after all, my entire raison d’être to assess them. Still. I had survived my bout with the virus and my long isolation. Very few viruses cause global pandemics or even human pathology of any kind. Most likely, this would burn out.

“Here,” Declan had said, thrusting a small insulated bag at me. “Keep it in the dry ice until you’re home.”

“What? What is this?”

“Right now it has the catchy name of DM-07945843-01. It’s the viral vector containing the nanobody. It didn’t work against the previous strains of artiovirus we tried, but what if it works against ART?”

I didn’t touch the bag. “Why would you give it to me?”

Declan met my gaze. “Insurance policy. If it gets bad here and something happens to me, I don’t want every sample of the drug in the entire world to be in one place. We have five extra doses right now and I’m giving you half of one of them, based on what we think the ED50 will be for a seventy-kilogram man.”

“Why give me a partial dose?”

“I don’t want you to be tempted to use it. I don’t know if it’s safe.”

“So send it to some big biopharma lab to safeguard it.”

“I’ll have to, probably soon, if we want to speed up. Listen, Kiki.” He grasped my hands. “I trust you. This drug represents most of my career. If you decide you’re pissed at me for some reason, you could ruin my life.”

“I would never do anything to harm you. But you don’t need to give me this.”

“I know. I want to. Just keep it in case something happens to me.”

I took him in. One last close-up: his black hair, threaded in front with a hint of silver, the intensity of those blue eyes. The vitality in his trim body. “You know what? I’m going to miss you.”

“Not as much as I’m going to miss you.”

Those were the last words I heard from Declan’s lips for quite some time. The drug sat in its little bag in an industrial-grade freezer, untouched, through the first wave of the pandemic. If Declan’s weight-based calculations were correct, I had enough drug to treat one person, weighing about eighty pounds. Rorie weighed more than this, and I’d have to hope it would still work for her; there was no way I could count on having enough to treat them both.