The monitors beeped and Wally flinched again. I knew the course his mind would chart: he’d realize—or he’d guess—where I had gotten this drug and why I hadn’t used it before. An untested drug: even with treatment, anaphylactic shock could kill the recipient. It could cause any number of other unforeseen problems. On the other hand, if it worked, it would save the life of my child based on a privilege other dying patients did not have. It was profoundly, elementally unethical to do what I was about to do. I waited for Wally’s reaction, knowing I would administer the drug no matter what he said.

“Can you split it?” he asked finally.

“No,” I said. “It’s dosed by kilogram and there’s not enough here to fully dose either of them. I can’t dilute it any further if I want one of them to have a chance. I have to choose.”

Wally didn’t ask the obvious question. He’d know who I picked in a moment anyway, when I administered the drug. I busied myself removing the outer foil from the lid of the tiny glass vial, revealing an aluminum ring with a spongy center. I swiped an alcohol wipe across it and plunged the tip of an 18-gauge needle into the vial, sucking the precious fluid inside into a syringe. When it had filled, I removed the needle, turned the syringe upside down, and tapped it.

“I’m going to give it to Rorie.”

—

DECLAN HAD GIVEN me the drug during those final, fraught moments in Spain last June, right before I’d stepped into the taxi that would take me to the airport in Seville. From there, the kids and I would catch a plane to Madrid and then home to Atlanta. We were tired and afraid; I’d endured a three-week separation from Declan and the children until I was released from isolation and could return to Seville. Both of us knew, with the illness in its infancy, it might be months or years before we saw one another again if the local epidemic went global. But at the same time, on some level, I hadn’t allowed myself to process the very real possibility that something could happen to him, or to any of us. The human brain isn’t equipped to deal with worst-case scenarios. Some mysterious psychological quirk protects us from believing in the validity of our nightmares, allowing us to dismiss bad things even as we acknowledge their existence. When this protective mechanism fails, we become paranoid and phobic, and when it works too well, we dismiss rational risk assessment in favor of sunshine and roses. Rarely do we strike the perfect balance.