Everyone has Kellis-Amberlee, but most of us have only one strain at a time. Some are more aggressive than others and will basically wipe out an existing infection in order to take over a body. The original Kellis-Amberlee strain developed when lab-clean Kellis flu met lab-clean Marburg Amberlee. That was the first infection anybody had to deal with, the one that swept the world during the Rising. It took years of study and analysis of the structure of the virus before anyone realized that it was doing what viruses have done since the beginning of time: It was mutating, changing to suit its environment. For a while, people hoped it was becoming less virulent and that it would eventually turn into something that didn’t do quite as much damage. Honestly, I think we’d have been happy if the virus just started killing people, rather than doing what it does now. At least then the dead would stay dead and the world could start moving on. Instead, Kellis-Amberlee has continued doing what it does best: making zombies and unleashing them on the world whenever it gets the opportunity.

I guess it’s consistent. That’s something, anyway.

“It’s correct,” said Mahir. His voice was dark, and there was something dangerous in his tone, something I’d never heard there before. He adjusted his glasses and continued: “There was a spike in deaths in Buenos Aires right before the substrain was isolated and identified for the first time. Eighty percent of the dead were confirmed as suffering from an early form of reservoir condition. It was five years before that substrain was identified in connection with a live reservoir condition.”

Kelly paled further.

“As part of his research into the behavior of the various substrains, Professor Brannon had access to census and death records from multiple parts of the world,” said Mahir. “Much of this data hadn’t previously been incorporated into the model—Dr. bbey is unable to acquire information through many normal channels, due to her lab’s lack of accreditation, Dr. Christopher’s focus is on treatment, not the structure of the virus itself, and Dr. Tiwari doesn’t do statistics.”

“I’m not following you,” I said.

“I am,” said Kelly. She directed her words at the wall, looking faintly stunned. “He’s saying that once they were able to feed the substrain analysis and the census data into the same model, they started getting some results they didn’t want to get. The kind of results a man who spent his life working to save lives would commit suicide over.”

Maggie frowned. “I thought results were sort of the goal.”