Mary blinked. “Me?”

“There aren’t that many female Canadian scientists who really make it big, but you have. Even before Ponter came along, you’d really put us on the map. The work you did with ancient DNA! First-rate! Absolutely first-rate! Who says that Canadian women can’t take the world by storm?”

“Um, thank you.”

“You’ve been quite the role model for me. You, Julie Payette, Roberta Bondar…”

Mary had never thought of herself in that august company—Payette and Bondar were Canadian astronauts. But, then again, she had gotten to another world before either of them…

“Thank you,” said Mary again. “Umm, we really don’t have that much time…”

Veronica blushed a bit. “Sorry; you’re right. Let me explain the procedure. The work I’m doing is based on research begun here at Laurentian in the 1990s by Michael Persinger. I can’t take credit for the fundamental idea—but science is all about replication, and my job is verifying his findings.”

Mary looked around the lab, which had the usual university mix of shiny new equipment, battered old equipment, and beat-up wooden furniture. Veronica went on. “Now, Persinger had about an 80 percent success rate. My equipment is second-generation, a modification of what he developed, and I’m getting about 94 percent.”

“It seems a bit of a coincidence that this research is going on so close to the portal between worlds,” said Mary.

But Veronica shook her head. “Oh, no, Mary, not really! We’re all here because of the same thing—the nickel that was deposited when that asteroid hit the Earth here two billion years ago. See, originally Persinger was interested in the UFO phenomenon: how come flying saucers are most frequently seen by guys named Clete and Bubba out in the back forty.”

“Well,” said Mary, “you can get beer anywhere.”

Veronica laughed more than even Mary thought the joke deserved. “That’s true—but Persinger decided to take the question at face value. Not that he, or I, believe in flying saucers, but there is a real psychological phenomenon that makes people think they’ve seen such things, and Persinger got to wondering why that phenomenon would be triggered outdoors, especially in isolated locations. Laurentian does a lot of mining studies, of course, and when Persinger started looking for possible causes for the out-in-the-countryside UFO experience, the mining engineers here suggested piezoelectric discharges.”

Ponter’s Companion, Hak, had bleeped a couple of times, indicating he hadn’t understood some words, but neither Ponter nor Mary had interrupted Veronica, who was clearly on a roll. Apparently, though, she didn’t expect Ponter to know the term “piezoelectric,” and so explained it of her own accord: “Piezoelectricity is the generation of electricity in rock crystals that are being deformed or are otherwise under stress. You get piezoelectric discharges, for instance, when a pickup truck drives over rocky ground out in the country—the classic UFO-sighting scenario. Persinger managed to reliably replicate that sort of electromagnetic effect in the lab, and lo and behold, he could make just about anyone think they’d seen an alien.”

“An alien?” repeated Mary. “But you’d mentioned God.”

“To-may-to, to-mah-to,” said Veronica, grinning a very toothy grin. “It’s all the same thing.”

“How?”

Veronica pulled a book off her shelf: Why God Won’t Go Away: The Biological Basis for Belief. “Newberg and d’Aquili, the authors of this book, did brain scans of eight Tibetan Buddhists meditating and of a bunch of Franciscan nuns praying. Naturally, those people showed increased activity in the areas of the brain associated with concentration. But they also showed decreased activity in the parietal lobe.” She tapped the side of her skull, indicating the lobe’s location. “The left-hemisphere part of the parietal lobe helps define your own body image, while the right-hemisphere part helps orient you in three-dimensional space. So, collectively, those two parts are responsible for defining the boundary between where your body ends and things outside your body begin. With the parietal lobe taking a coffee break, the natural feeling is exactly what the monks report: a loss of the sense of self, and a feeling of being at one with the universe.”

Mary nodded. “I saw the cover story about that in Time.”

Veronica politely shook her head. “It was Newsweek, actually. Anyway, their work combines with Persinger’s and mine. They found that the limbic system lights up during religious experiences—and it’s the limbic system that tags things as significant. You can show a parent a hundred babies, but they’ll only react profoundly to the sight of their own baby. That’s because the limbic system has tagged that particular visual input as important. Well, with the limbic system afire during religious experiences, the whole thing gets tagged as overwhelmingly important.

“That’s why religious experiences never sound good in the telling: it’s just like me telling you my boyfriend is the best-looking guy in the world, and you going, yeah, sure. So I open my purse and show you a picture of him, and I think you’ll be convinced, right? You’ll go, wow, he is a hunk. But if I did that, you won’t have that response. He’s handsome beyond compare to me because my limbic system has tagged his appearance as having special significance for me. But there’s no way I can express that to you via words or pictures. Same thing with religious experiences: no matter how much someone tells you about their own one, about how life-changing and momentous it was, you just can’t get that same feeling about it.”

Ponter had clearly been listening intently, alternately frowning his wide mouth and rolling his continuous blond eyebrow up his doubly arched browridge. “And you believe,” he said, “that this thing your people have and mine do not—this religion—is tied to the functioning of your brains?”

“Just so!” said Veronica. “A combination of parietal-lobe and limbic-system activity. Look at what happens in Alzheimer’s patients: people who’ve been devout their whole lives often lose interest in religion when they come down with Alzheimer’s disease. Well, one of the first things Alzheimer’s does is cripple the limbic system.”

She paused, then continued. “It’s long been known that so-called religious experiences are tied to brain chemistry, since hallucinogenic drugs can induce them—which is why such drugs form the basis of ritual in so many tribal cultures. And we’ve long known that the limbic system might be one of the keys: some epileptics with seizures restricted to the limbic system have incredibly profound religious experiences. For instance, Dostoevsky was an epileptic, and he wrote about ‘touching God’ during his seizures. Saint Paul, Joan of Arc, Saint Theresa of Avila, and Emanuel Sweden-borg were all probably epileptics, too.”

Ponter was leaning now against the corner of a filing cabinet, unself-consciously shimmying left and right, scratching his back. “Those are the names of people?” he asked.

Veronica was briefly taken aback, then nodded. “Dead people. Famous religious people of the past.”

Mary took pity on Ponter at this point and explained “epilepsy” for him. Ponter had never heard of anything like it, and Mary wondered—with the shiver she got whenever she contemplated it—whether epileptic genes were yet another thing the Neanderthals had dispassionately purged from their gene pool.

“But even if you’re not epileptic,” Veronica said, “you can get that effect. Ritual dancing, chanting, and so on have been independently developed over and over by religions around the globe. Why? Because the deliberate, repetitive, stylized body movements during such ceremonies make the limbic system tag them as being of special significance.”

“This is all well and good,” said Mary, “but—”