“Say that were true. How would the bacteria survive for more than six hundred years underground?”

“Who knows? Maybe it survived in some kind of spore form? Other bacteria do. For example, C. difficile can live dormant as spores for years. A kind of suspended animation.”

“Six hundred years? Seems like a stretch.” He frowns. “Even if we assume the microbe did originate somewhere in the monastery, how did it travel all the way across the city to Parco Serra Gropallo to become endemic in the rat population there?”

Alana just stares at him, lost for a plausible explanation.

The silence is broken by a loud voice. “There you are!”

Alana looks over to see Justine Williams striding toward them.

“Finally. It’s like finding two annoying needles in a haystack. Hey, boss,” Justine says to Byron. “I’m not asking for one of your kidneys or anything, but how about checking your phone every once in a while?”

“What is it, Justine?” he asks evenly.

She motions from the glass to the bottle. “Since I didn’t get the memo about the pub crawl, I decided to get a little work done on preventing the next apocalypse.”

“Are you going to get the point?” Alana asks.

“Eventually. I’m not quite done guilt-tripping you two for drinking on the job. And worst of all, without me!” Justine grabs a nearby chair and pulls it up to the table. “Okay, we just got the results on the rats we found in the park.”

“And?” Alana prompts.

“We found Xenopsylla cheopis. Classic rat fleas. Lots of them. And according to the rapid PCR screen on their saliva, the little buggers are carrying Yersinia.”

“But that’s not a big surprise,” Byron says. “We knew the rat died of the plague.”

Justine shrugs. “Who said anything about the dead rat?”

“Hold on,” Alana says, thinking she must have misunderstood. “You’re saying you found infected fleas on the live rats?”

“All the rats! Including the live ones. The big aggressive male. His fleas were loaded with the plague.”

“The healthy one?” Alana asks, pushing herself up from the table.

“Healthy as a horse. Well . . . not so much after we euthanized him. We’re going to do a necropsy, of course, but there’s no sign he ever had the plague.”

“Then he must have recovered from it,” Byron suggests.

“Nope.” Justine shakes her head so hard her hair shakes. “There’s zero evidence he was ever sick with the plague.”

Alana feels on edge and, suddenly, fully sober.

“Justine, are you saying this rat was an asymptomatic carrier of plague-infected fleas?” Byron asks.

“You catch on quick for a Canadian.”

Alana squeezes her temples between her palms. “So now we have rats that are immune to plague but can still spread the goddamn Black Death.”

Chapter

Thirty-Six

Kemal Attila doesn’t smoke, but he’s happy to keep his younger brother, Basim, company, if only to escape the stagnant heat inside their father’s convenience store. There are no customers anyway. Business is bad this week. Ever since the news of the plague broke. Kemal doesn’t understand the big deal, but since he’s facing a mountain of schoolwork at the university, he’s happy for the quiet.