“Sure we can get diseases from pigs, and yes, they are genetically similar. I’m not saying this is from a pig, however. Antigenic shifts in viruses can come from a whole bunch of animals—pigs and bats and birds quite a lot of the time. But those have been other viruses. Artioviruses haven’t been much on the radar for serious human disease, although they can cause significant pathology in animals. There are twenty or thirty types, and of those, six of them can affect us, but aside from cold symptoms, it’s only been weird lesions in sheepherders, that kind of thing. Nothing major.”

Vani said, “That’s a quick turnaround, isn’t it? For genetic sequencing of an entire virus?”

“Well, not really. An RNA virus is extremely simple compared to a human genome. But also: we’ve gotten a lot faster. It took scientists almost six months to determine the cause of the SARS epidemic in 2003; by 2013, when the H7N9 avian influenza epidemic hit, it took about one month to sequence the virus. Now with next-gen sequencing, it can be only hours, even for a complex genome.”

Declan had closed his eyes. He sat without moving, his back extremely straight, directing his question to Kira. “Do the reports say anything else about the human cases?”

Kira bent her head back to her phone. “There’s a ton of stuff here . . . let’s see. There are more case reports in Spain—a handful—but I’m not seeing as much for Morocco, just a couple. They’re still saying there’s no evidence for human-to-human transmission, but of course caution is urged. No cases reported in medical personnel who’ve been treating the patients. So that’s good.”

“So,” said Georgia. “We go?”

They were scheduled to spend the day in Seville, touring the palace and the cathedral, and then tomorrow they’d rent a van for the drive to Tarifa, where all of them, including the children, would catch the ferry to Morocco.

“Yes, I think so,” said Kira. “But I may need to fly home after that.” She stood, her cell phone already to her ear, and waved at Declan to follow her. “Excuse us, we’re going to step away for a moment.”

Hannah’s eyes followed Kira until she and Declan stopped at a point down the street, speaking to one another with some intensity. Just past the two of them jutted the border of the resplendent grounds of Real Alcázar, the palace constructed for the Christian king Peter of Castile. The stones of this building, steeped in thousands of years of historical significance, must have borne mute witness to a staggering amount of disease and death. Whatever was happening now, with this new virus, would not be new to them.