“And how do you specify the output?” asked Mary, staring at the machine in fascination.

“One way is by voice,” said Vissan. She pulled out a control bud and addressed the device. “Produce a string of deoxyribonucleic acid 100,000 nucleotides long, consisting of the codon adenine-cytosine-thymine over and over again.” She looked at Mary. “That’s the code for the amino acid—”

“For threonine,” said Mary.

Vissan nodded. “Exactly.”

Several green lights appeared on the device. “Ah, there—it’s saying it needs to be fed raw materials.” She pointed to the screen. “See? They’re specified here. Anyway, you can also use one of several keypads to input data.” She pointed at a toggle switch. “You select either deoxyribonucleic-acid or ribonucleic-acid mode here. And then you can input data at any level of resolution, right down to individual nucleotides.” She indicated a square arrangement of four buttons.

Mary nodded. The toggle must have been set for DNA mode, since the buttons were displaying the Neanderthal glyphs for adenine, guanine, thymine, and cytosine. She pointed to another cluster of buttons, arranged in an eight-by-eight grid. “And these must be for specifying codons, right?” Codons were the words of the genetic language, and there were sixty-four of them, each consisting of three nucleotides. Each codon specified one of the twenty amino acids that are used to make proteins. Since there were more codons than there were amino acids, multiple codons meant the same thing—genetic synonyms.

“Yes, that’s right,” said Vissan. “Those buttons let you choose codons. Or, if you do not care which codon is used to specify a given amino acid, you can just select the amino acid by name here.” She pointed at a cluster of twenty buttons, arrayed in four lines of five.

“Of course,” continued Vissan, “these controls are normally only used for fine editing; it would be incredibly tedious to specify a lengthy deoxyribonucleic-acid sequence by hand. Normally, one interfaces this device to a computer and simply downloads the genetic design one wishes to manufacture.”

“Amazing,” said Mary. “You wouldn’t believe the gyrations we go through to do gene splicing.” She looked at Vissan. “Thank you.”

“My pleasure,” said Vissan. “Now, let’s get down to work.”

“Now?” said Mary.

“Of course. We won’t produce the actual DNA, but we’ll get the process set up. First, we’ll take samples of your deoxyribonucleic acid and Ponter’s, and then sequence them.”

“You can do that here?”

“The codon writer can. We just feed in a sample of deoxyribonucleic acid, and let it analyze it. It should take about a daytenth for each specimen.”

“Only a daytenth to sequence an entire personal genome?” said Mary, astonished.

“Yes,” said Vissan. “Let’s get it started, and then I’ll go catch us something to eat.”

“I’d be glad to help in the hunt,” said Ponter. He smiled and raised a hand. “Although I know you don’t need it.”

“I would welcome the company,” said Vissan. “But first, let’s collect some genetic material from each of you…”

Ponter called the travel-cube driver and told him to head back to Kraldak; they would summon another cube later in the day to take them home.

Mary and Mega stayed back in the cabin, while Vissan and Ponter went off hunting. Mega showed Mary how her new toy worked; Mary paraphrased part of Kipling’s The Jungle Book for Mega; and Mega taught Mary to sing a short Neanderthal song. It was a kick spending time with Mega—and Mary knew it would be even more wonderful to have a child of her own.

Finally, Vissan and Ponter returned with a pheasant they’d caught for dinner, which Vissan proceeded to cook while Ponter made a salad. It turned out there were solar panels on the roof of Vissan’s cabin, and she had a vacuum box for storing food, an electric heater, some luciferin lamps, and more; friends had given her farewell gifts when she’d chosen to leave structured Neanderthal society. All in all, Mary thought it actually might not be that bad a life, as long as one had plenty to read. Vissan showed Mary her datapad, and how she could recharge it from the solar array on the cabin’s roof. “I have some four billion words of text stored on this,” she said. “My access to new works has been cut off, of course—but that’s all right; the new stuff is all garbage, anyway. But the classics!” Vissan hugged the little device to her chest. “How I love reading the classics!”

Mary smiled. Vissan sounded just like Colm, extolling the virtues of Shakespeare and his contemporaries; she’d had to keep her Harlequin romances out of his sight, lest an argument ensue.

The dinner was delicious, Mary had to admit—or maybe, she reflected, she was just famished after all the hiking she’d done that day.

The codon writer had been moved to the floor during dinner, but once they’d finished eating, Vissan lifted it back up onto the table. Mega curled up in a corner and had a nap, while the three adults sat around the table: Vissan on the one chair, Ponter on the end of a log, and Mary, facing the cyclopean mammoth skull, perched atop the vacuum box.

“All right,” said Vissan, peering at the display. “It’s finished sequencing.” Mary was looking at Vissan, rather than the square screen, since, with a few exceptions that she’d picked up along the way, she couldn’t understand the glyphs it was showing. But Vissan was oblivious to that, and pointed at the screen. “As you can see, it’s made a list of the 50,000 active genes in your deoxyribonucleic acid, Mare, and the 50,000 in Ponter’s.”

“Fifty thousand?” said Mary. “I thought there were only 35,000 active genes in human DNA. That’s our latest count.”

Vissan frowned. “Ah, well, you’re missing out on…I’m not sure what you call it. A kind of exonic redoubling. I can show you later how that works.”

“Please,” said Mary, fascinated.

“In any event, the device has now made a list of 50,000 gene alleles you each possess. That means the codon writer could now just go ahead and produce what you need: a pair of gametes that have the same number of chromosomes. But…”

“Yes?” said Mary.

“Well, I told you the original intention of this device: to let parents pick and choose from the alleles they could offer a child.”

“I think we’ll be happy to just try our luck randomly.” The words were out before Mary really had time to think about them; perhaps, she realized, it was some of her natural Catholic revulsion at tinkering with the stuff of life coming to the surface…although any use of this machine certainly qualified as major tinkering!

Vissan frowned. “If you were both Barasts, I would be content to accept that answer—but then again, as you yourself observed, Mare, if you were both Barast, you wouldn’t need the codon writer just to randomly combine your genetic material.” She shook her head. “But you are not both Barasts.” She looked down at Ponter’s forearm. “I never thought I’d use one of these again, but…Companion of Ponter!”

“Healthy day,” said a male voice from the device’s external speaker. “My name is Hak.”

“Hak, then,” said Vissan. “Surely studies have been done of the differences between Barasts and Gliksin deoxyribonucleic acid since contact was made with Mare’s people?”

“Oh, yes,” said Hak. “It has been quite the hot topic.”

“Are those studies available through the planetary information network?”

“Of course.”

“Good,” said Vissan. “We will need to access them as we go along.” She looked up and shifted her gaze from Mary to Ponter, then back to Mary again. “I strongly advise against just slapping your deoxyribonucleic acid together. We are talking about combining two species here. Now, yes”—she gestured at the codon writer’s screen—“it’s clear that the genomes for Barasts and Gliksins are almost identical, but we should really examine where they diverge, and carefully select combinations.” She pointed at Mary. “Are tiny noses like that typical of your species?”