A ghost of a smile flickered. “You and Ruby both. Ruby brought me her family’s chicken-barley soup. She was so hurt when I turned it down, but I’m a vegetarian.”

“Lentils,” I said. “Come to Chicago when all this is behind us. I’ll make you my mother’s lentil soup. What do you have for me?”

The autopsy on Dr. Roque had been completed last night. “He had contracted plague, and perhaps that would have killed him, but he collapsed in the lab because somebody had stabbed him. The killer knew how to stay away from the cameras monitoring the autopsy room, so there is no recording of the attack. It is not possible to know who went into the lab and attacked him.”

“You said you were listening to him as he was dictating,” I reminded her.

“This person moved quietly. Dr. Roque did not cry out or say anything. Maybe it was even someone he was used to seeing.”

If that was the case, it should make it easier for the police to find a suspect. “They wanted to remove the dead woman before Dr. Roque worked on her so that she couldn’t be identified,” I added, thinking out loud.

“Is that a reason enough?” Aanya flashed back. “The only consolation Dr. Madej could give me was to say that Dr. Roque was spared a painful death from the plague. And Dr. Madej thinks he and Dr. Hitchcock may both have contracted the illness from the soil samples.”

“So someone deliberately contaminated the soil that Doris McKinnon collected?” I asked.

“Not necessarily deliberately. Since it came from a farm, if infected rats or chickens or even prairie dogs were nearby, they could have left plague in the ground. The organism occurs naturally in the wild. It isn’t only the product of some diabolical plan to spread disease. It can sometimes survive in soil up to three months after an infected animal dies.”

I told Aanya what I’d been thinking this morning, about Kiel’s old experiment and the possibility of someone—Spirova—switching the bacteria.

“It is possible, yes, that such a thing happened thirty-five years ago, but believe me, Vic, those old microbes would not be still alive in that woman’s farm. Three months or less would be a maximum lifetime for them outside a live host, and that is under the conditions that are most ideal for the bacillus.”