“Nathan?” I kept my voice low, like I was speaking to a panicky animal. In a way, maybe I was. My still-pounding heart was doing its best to remind me that humans were just animals, as subject to the whims and whimsies of biology. The fight or flight response was wreaking havoc with both of us.

I’d always wondered why I sometimes passed out before I really panicked, despite everyone I knew working almost exactly the opposite. If “I” was a separate beast from the brain that stored my memories and emotional response, though, it started to make sense. Too much adrenaline flooded the mind, and I got knocked out of the synaptic loop, resulting in a loss of consciousness but not total loss of cool. Inefficient. Doubtless unintentional, too. So much about my design was.

“We don’t know what the lobby’s going to look like.” Nathan’s voice was soft, uninflected—virtually dead. If I hadn’t known that he’d never been fitted with an implant, I would have rethought my position on panic when I heard him speak. “If there are sleepwalkers there, if it’s dangerous, take the dogs and run. I’ll hold them off so that you can get away.”

“And go where? Nathan, I can’t drive. I never learned, and even if I had, I’d never be able to make myself drive away and leave you. We could run off down the street, but if the situation is that bad, we’d just be eaten by the next swarm of sleepwalkers we saw. We’re staying with you. We’re staying together. That’s the only way that we’re going to get out of this. Together.” I forced myself to smile. “Besides, you know your mother would kill me if I called her from the Concord BART Station and said, ‘Hey, I left your son to die but I made it to the train, do you think you could come and pick me up?’ ”

Nathan chuckled.

The floor indicator counted down from three to two.

My hands were full, and I didn’t dare let go of anything I had. Nathan had already dropped his suitcase, and the mere fact that he would prioritize my dog—our dog—over the only personal possessions he had been able to save made me even more certain that marrying him was the right course of action. He didn’t care that I was a tapeworm in a human skin, but he cared about proper leash etiquette. I was never going to find a more perfect man.

“I love you.”

“I love you, too.”

The counter reached one with a soft “ding,” and the elevator doors opened to reveal an anticlimactically empty lobby. I blinked, unable to believe what my eyes were seeing. Only Minnie tugging on the leash as she eagerly tried to pull me out of the elevator to the walkies she assumed were waiting for her snapped me out of my fugue.

“Run,” said Nathan, stuffing the knife back into his waistband and grabbing his previously discarded suitcase.

We ran.

The street outside the apartment building was eerily deserted, as if all of San Francisco had suddenly realized they had better things to do than their afternoon commute. Two people, both bloody, running with suitcases and dogs out of a private building and into an equally private parking lot, should have attracted some attention of the police persuasion. We saw no one, and if anyone saw us, they didn’t bother contacting the authorities—or maybe they did, and the systems had already reached the point of overload. That was a question that would never be answered, because there wasn’t time to stop and ask, and there were more important things for us to do. Like escaping the prison that San Francisco was about to become.

We threw our suitcases into the trunk, placing the terrarium with only slightly more care, and loaded the excited, overstimulated dogs into the backseat before getting into the front. Nathan waited for me to buckle myself in before he hit the gas, but only barely. For once, my phobias were going to have to take second place on the list of priorities, and even as I swallowed the rising tide of panic—and the rising bile in my throat—I agreed with this decision. I could have hysterics when we got out of this.

The drums were back in my ears, pounding steadily and reassuringly. I wondered what my tendency to freak out in cars meant for my “Sal passes out before the chemicals can make her panic” theory, and decided that since this particular strain of panic was psychological, not triggered by physiological reactions, it ran according to a different set of rules, even though the actual biochemistry probably wasn’t all that different. This question kept me occupied for almost six blocks, which made it worth the contemplation. Anything to distract me from the way that Nathan was driving.

Then I glanced up, and frowned as I recognized the neighborhood around us. “Nathan, where are you going? This isn’t the way to the Bay Bridge.”

“That’s because we’re taking another route,” he said. “There were too many sleepwalkers there, and that was hours ago. By now the area has either completely devolved into chaos, or the authorities have it locked down. We’d be lucky if they let us onto the bridge at all. If we were particularly unlucky, they’d take one look at us and haul us off for medical testing. I don’t know about you, but I didn’t escape from that apartment building just so I could go into quarantine.”

“I don’t want that either,” I assured him. “So where are we going?”

“Down the coast to the San Mateo Bridge. It’s going to be a longer drive, and I’m really sorry about that. I should be able to slow down once we’re past the airport.”

I forced myself to nod as if I was okay with this plan, as if it didn’t make me want to fling myself screaming from the car. “I may try to sleep, if that’s all right with you. I don’t know if I can, but it would give me something else to focus on.”