"It was natural to look at squirrels when I decided to study genetic variability," Professor White began. "The campus is full of them, and the cars and groundskeepers keep hitting them. I needed something cheap, you know. The university doesn't have much of a research budget for retired professors, and I need to keep my mind busy."

I nodded, trying, at least, to appear sympathetic. Back when I was in grade school, she had been a research superstar. Her resume lists a dozen papers in Science, several in Cell, and a couple in Nature, but she is 75 now, and those papers were all at least a decade old.

"Gray squirrels pose some interesting questions, you know, because they live in both city and country environments. Urban squirrels behave differently. Before they cut down the trees to build that ugly parking lot, the squirrels used to sit on a branch just outside the window and stare at me. Rural squirrels don't do that. I wondered if that difference in urban behavior reflected genetic drift. I thought someone should have done some genetic sequences on them, but I couldn't find anything in the literature. You wouldn't believe how far computerized databases have come. Do you use them in the research administration office?" A dreamy expression crossed her face and she glanced out the window at the parking lot.

"Are you sure there's nothing on squirrels?" I asked, trying to keep her attention. The provost had warned me, when he asked me to check on her, that her mind wandered.

She turned back, her sharp blue eyes staring into mine. "Of course. Squirrel genetics were beneath them. They were vermin. The animals, that is. Mice and rat genetics were known, what geneticist wanted to bother with squirrels?"

My digital voice recorder took it all in; I love new toys, and I could see her office didn't have anything newer than a five-year-old computer. "What did you find?"

"Not what I expected. There were two distinct genetic patterns in city squirrels, but only one was present in the country." She looked down at the single folder of papers on her clean desk. "The genetic-variation statistics are odd. Very odd."

"How so?"

"Natural populations show bell-curve distributions of many characteristics. The rural squirrels did, and so did the city squirrels without the odd genes. The two patterns matched except for a very minor genetic drift that might be the start of the urban squirrels learning to look out for cars, or some such thing."

"What about the others?"

"On superficial examination of their anatomy, they were identical with the other squirrels. Yet, they showed no real genetic variation among themselves, like inbred white mice."

"Do you have an explanation?" The provost had heard she had some very odd ones.

"I thought someone here at the university might have released some inbred squirrels after experimenting on them. Or maybe there had been some natural inbreeding on campus. To check those theories, I examined other populations. I spent several months driving around the city, collecting roadkilled squirrels. Two months ago, I flew to Chicago to visit my nephew and made more collections there."

I nodded. That was something else that worried the provost.

"I found the same populations in the rest of the city and in Chicago. The fractions weren't always the same, but some urban squirrels everywhere have the same odd extra genes. The extra genes are homogeneous. Remarkably, unnaturally homogeneous. I think they're bioengineered clones."

"Oh!" Although the recorder was taking everything down, I wrote it on my notepad as a point to stress to the provost. "Who could have released them?"

"I wondered that, myself. Did you know that one of the fraternities had a stuffed squirrel that someone had caught on campus back in the thirties?"

"Was that the one that disappeared from their house three weeks ago?"

She nodded, her eyes sparkling impishly. "The very one. Thanks to PCR, I was able to extract a fair amount of DNA from the skin. It was one of the bioengineered clones."

"But that's impossible. Nobody could do bioengineering during the Great Depression."

"No, it's not impossible, because we aren't doing the bioengineering. Someone else is, young man. Someone else has been for a long time. You know, I used to think people were crazy when they said they thought they were being watched. But now I know they were right. We are being watched by squirrels genetically engineered to be living tape recorders. And that's why I called the provost, because we really have to get the word out to the public about this. I can't do it all myself, not at my age."

I nodded as her story grew wilder. Nutty as a fruitcake, as my grandmother used to say. Professor White had devised a very elaborate conspiracy theory, blaming mysterious aliens for genetically engineering squirrels that had spied on people for decades. She hadn't found the aliens, but she was sure they still were collecting data from the squirrels. "I'd never admit it to the construction office, but now I don't mind that they took those big trees down," she told me, pointing toward the parking lot.

When four o'clock came, I thanked her and excused myself. Walking down the hall, I pushed the "duplicate" button on the recorder. The provost would be happy. The recording should convince the faculty's administrative conduct committee that the old woman was suffering from paranoid delusions, so they should revoke her laboratory privileges.

I checked my watch. My appointment with the provost was at 4:30, so I had time for a quick call. I found a quiet corner and pushed the memorized codes on my mobile phone. After a delay from scrambling and descrambling, a familiar voice answered.

"Just the squirrels," I said. "She never suspected the pigeons."