“What time is it?” she called through the open door. Her mind was clearing, and the dizziness she’d experienced when first getting off George’s bed had totally disappeared.

“It’s about two, a little after,” said George. “You want something to eat?”

“No! There’s no time. We have to get moving. The longer we wait, the less chance we have of finding anything. As we learned, polonium has a relatively short half-life and you can just wash it off normally, like dirt.”

“So you’re sticking to the polonium idea?” George had half hoped Pia would have cooled to her rather outlandish scenario by the time he got back.

“Absolutely. It fits so well. You agreed it fit, didn’t you?”

“It seems to,” George said. “Provided we can’t think of another reason for the hair loss. But the practicalities seem so daunting. And you’re sure there was hair loss, right?”

“Oh God, yes, George, I’m sure. You saw it yourself.”

George looked at Pia as she emerged from the bathroom. She had an intent expression on her face. It seemed that Pia was pleased with the power of her deductive reasoning, or else with the elegance of the plot to murder her mentor.

“Do you have any idea how hard this must have been to pull off?” she said. “It makes the Kennedy assassination look easy.”

“I think Oswald acted alone.”

“Okay, bad example. This has to be a sizable conspiracy, with a number of people involved. Once we confirm the polonium, I can’t let the authorities spin the story, which they will. I need to make sure my version of the story, which is the truth, gets out.”

“But if there’s proof, the police will protect you.”

“Bullshit. It’s the police I’m most afraid of. Listen, the more I think about it, the more I think it has to have been other researchers or doctors. The science behind it is impressive. I mean, it had to be someone with a medical background who thought all this through. Otherwise, as you said, why not just shoot them?” Pia stopped herself.

“I’m jumping the gun. We’ve got to look for radiation left in the lab. If it’s going to be anyplace, that’s where it will be, I’m sure. We need that Geiger counter. But let’s make a quick detour back to my room. I need to dig out some concealer. The fact that I look like I got run over is going to raise some eyebrows.”

“Let’s make it quick,” George said. “I’ve only managed to wrangle a couple more hours. I have to be back in the Radiology Department for an important lecture at four o’clock.”