Reuben moved forward and showed him an ID card. “I’m Dr. Montego, the mine-site physician here, and this is a medical emergency. Krieger may be highly infectious.”

“I should call my superior,” said the soldier.

“Do that,” snapped Reuben. “But first tell us what he was carrying.”

The man frowned, thinking. “One of those overnight bags that rolls on wheels.”

“Anything else?”

“Yes, a metal box, about the size of a shoebox.”

Reuben looked at Mary. “Damn,” she said.

“Was the box put through decontamination?” asked Louise. “Of course,” said the soldier, his tone defensive. “Nothing goes through without being decontaminated.”

“Good,” said Mary. “Let us through.”

“Can I see your identification?”

Mary and Louise slapped their passports down. “All right?” said Mary. “Now, let us through.”

“What about him?” said the soldier, pointing at Reuben.

“Damn it, man, I just showed you my Inco card,” said Reuben. “I don’t have my passport with me.”

“I’m not supposed to—”

“For Pete’s sake!” said Mary. “This is an emergency!”

The soldier nodded. “All right,” he said at last. “All right, go ahead.”

Mary ran on, leading the way to the Derkers tube. As soon as she got to its mouth, she continued on through, and—

Blue fire.

Static electricity.

Another world.

Mary could hear two sets of footfalls behind her, so she didn’t look back to see if Louise and Reuben were following as she hurried out of the tube. A burly male Neanderthal technician looked up, astonished. Probably no one had ever come running out of the portal before.

The Neanderthal was one Mary knew on sight. He clearly recognized her, too, but, to Mary’s astonishment, he was making a beeline to tackle Reuben, who was just behind Mary.

Mary suddenly realized what was going on: the Neanderthal thought Louise and Reuben were chasing Mary, not following her. “No!” shouted Mary. “No, they’re with me! Let them pass!”

Her own shouting meant that Christine had to wait until she’d finished her exclamation before translating the words, lest her external speaker—capable of a healthy volume, but nowhere near as loud as a shouting human—be drowned out. Mary listened to the Neanderthal words that came from her forearm: “Rak! Ta sooparb nolant, rak! Derpant helk! ”

By about halfway through the translation, the Neanderthal technician tried to abort his run, but he slipped on the polished granite computing-chamber floor and went sliding into Reuben, sending the M.D. flying. Louise tumbled over the Neanderthal, somersaulting onto her back.

Mary reached down and helped Louise up. Reuben was getting to his feet, too.

“Lupal! ” called the Neanderthal. Sorry!

Mary headed up the half flight of stairs into the control room, passing another startled Neanderthal, then continued on toward the drift that connected the quantum-computing facility to the rest of the nickel mine.

“Wait!” shouted the second Neanderthal. “You have to go through decontamination!”

“There’s no time,” Mary shouted back. “This is an emergency, and—”

But Reuben interrupted her. “No, Mary, he’s right. Remember how sick Ponter got when he first came to our side? We’re trying to prevent a plague, not start one.”

Mary swore. “All right,” she said. She looked at Reuben and Louise, the black Jamaican-Canadian with the shaved head and the pale Québecois with the long brunette hair. They’d doubtless seen each other naked many times, but neither had seen Mary that way. “Strip down,” she said decisively. “Everything off, including watches and jewelry.”

Louise and Reuben were used to decontamination procedures from working at the Sudbury Neutrino Observatory, which had been kept in clean-room conditions until Ponter’s original arrival destroyed the detector. Still, they each hesitated for a moment. Mary started undoing her blouse. “Come on,” she said. “There’s no time to waste.”

Reuben and Louise began removing their clothing.

“Just leave your clothes here,” said Mary as she tossed her panties into a round hamper. “We can pick up Neanderthal clothing in the next room.”

Mary, now totally nude, entered the cylindrical decontamination chamber. It had been designed to comfortably hold one adult Neanderthal, but at Mary’s insistence, all three of them piled into it, in order to save time. Mary was too nervous to be embarrassed as Louise’s backside pressed against her own, or as Reuben, who had ended up facing toward Mary, was pressed face first against her breasts.

Mary pulled out a control bud. The floor started slowly rotating, and lasers began firing. Mary was used to the procedure by now, but she could hear Louise gasp as the formidable-looking beam emitters hummed to life.

“It’s okay,” said Mary, trying to ignore the part of her brain that was calculating exactly what portions of Reuben were pressed up against her. “It’s perfectly safe. The lasers know which proteins should be in a human body—including those in intestinal bacteria, and so on—and they pass right through them. But they break down foreign proteins, killing any pathogens.”

Mary could feel Louise squirm slightly, but she sounded fascinated. “What kind of lasers can do that?”

“Quantum-cascade lasers,” said Mary, parroting something she’d heard Ponter say. “In the trillion-cycles-per-beat range.”

“Tunable terahertz lasers!” exclaimed Louise. “Yes, of course. Something like that could selectively interact with large molecules. How long does the process take?”

“About three minutes,” said Mary.

“Say, Mary,” said Reuben. “You should have someone look at that mole on your left shoulder…”

“What?” said Mary. “Jesus, Reuben, this isn’t the time—” But she cut herself off, realizing he was doing exactly what Louise had just been doing: retreating into a technical mind-set, trying to keep professional. After all, Reuben was buck naked with two women, one of whom was his lover and the other his lover’s friend. The last thing he—or Mary—needed right now was for him to be composing a letter to Penthouse in his head. “I’ll see a dermatologist,” she said, softening her tone. She shrugged as much as the tight confines would allow. “Damned ozone layer…”

Mary rotated her head slightly. “Louise, there should be a square light above the door in front of you. Do you see it?”

“Yes. Oh, it’s green! Good.” She shifted slightly, as if making to exit.

“Freeze!” snapped Mary. “Green is the Neanderthal color for ‘halt’—green meat is rotten meat. When it turns red, that means it’s okay to proceed. Let us know as soon as it does.”

Louise nodded; Mary could feel the back of the younger woman’s head going up and down. Maybe it had been a mistake to bring along two people who had had no preparation for the Neanderthal world. After all, it could be—

“Red!” exclaimed Louise. “The light is red!”

“All right,” said Mary. “Push the door open. The handle looks like a starfish—see it? It slides up to unlatch the door.”

Mary could feel Louise squirming some more, and then suddenly the pressure was off Mary’s back as Louise stepped out of the chamber. Mary took a backward step, turned around, and hurried out of the chamber as well. “This way!” she shouted.

They entered a room whose walls were covered with cubic cubbyholes, each containing a set of Neanderthal clothes. “Those should fit you, Reuben,” said Mary, pointing at one set. “And those should do for you,” she said, indicating another.

Mary was an old hand now at getting into Barast garments, but Louise and Reuben were clearly baffled. Mary shouted instructions at Reuben, and bent down next to Louise, who was having trouble with the footwear built into the Neanderthal pants. Mary did up her instep and ankle ties for her.

They then hurried out into the drift. Mary had hoped there would be a vehicle of some sort waiting there, but, of course, if there had been one, Jock himself would have taken it.