Carl, the elder of Don and Sarah’s two children, was known for his theatrics, so Don was grateful that he didn’t spurt coffee all over the table. Still, after swallowing, he managed to exclaim "You’re going to do what?" with vigor worthy of a sitcom. His wife Angela was seated next to him. Percy and Cassie — in full, Perseus and Cassiopeia, and, yes, Grandma had suggested the names — had been dispatched to watch a movie in Carl and Angela’s basement.

"We’re going to be rejuvenated," repeated Sarah, as if it were the most natural thing in the world.

"But that costs — I don’t know," said Carl, looking at Angela, as if she should be able to instantly supply the figure. When she didn’t, he said, "That costs billions and billions."

Don saw his wife smile. People sometimes thought their son had been named for Carl Sagan, but he wasn’t. Rather, he was named for his mother’s father.

"Yes, it does," said Sarah. "But we’re not paying for it. Cody McGavin is."

"You know Cody McGavin?" said Angela, her tone the same as it would have been if Sarah had claimed to know the Pope.

"Not until last week. But he knew of me. He funds a lot of SETI research." She shrugged a little. "One of his causes."

"And he’s willing to pay to have you rejuvenated?" asked Carl, sounding skeptical.

Sarah nodded. "And your father, too." She recounted their meeting with McGavin.

Angela stared in open-mouth wonder; she had mostly only known her mother-in-law as a little old lady, not — as the news-sites kept calling her — "the Grand Old Woman of SETI."

"But, even if it’s all paid for," said Carl, "no one knows what the long-term effects of — of — what do they call it?"

"A rollback," said Don.

"Right. No one knows the long-term effects of a rollback."

"That’s what everyone says about everything new," said Sarah. "No one knew what the long-term effects of low-carb dieting would be, but look at your father. He’s been on a low-carb diet for forty years now, and it’s kept his weight, cholesterol, blood pressure, and blood sugar all normal."

Don was embarrassed to have this brought up; he wasn’t sure that Angela knew that he used to be fat. He’d started putting on weight during his Ryerson years, and, by the time he was in his early forties, he’d reached 240 pounds — way too much for his narrow-shouldered five-foot-ten frame. But Atkins had taken it off, and kept it off, he had been a trim 175 for decades. While the others had enjoyed garlic mashed potatoes with their roast beef this evening, he’d had a double helping of green beans.

"Besides," continued Sarah, "if I don’t do this, nothing else I start today will have any long-term effects — because I won’t be around for the long term. Even if twenty or thirty years down the road this gives me cancer or a heart condition, that’s still twenty or thirty additional years that I wouldn’t have otherwise had."

Don saw a hint of a frown flicker across his son’s face. Doubtless he’d been thinking about when his mother had cancer once before, back when he’d been nine.

But it was clear he had no comeback for Sarah’s argument. "All right," he said at last. He looked at Angela, then back at his mother. "All right." But then he smiled, a smile that Sarah always said looked just like Don’s own, although Don himself couldn’t see it. "But you’ll have to agree to do more babysitting."

After that, everything happened quickly. Nobody said it out loud, but there was doubtless a feeling that time was of the essence. Left untreated, Sarah — or Don, for that matter, although no one seemed to care about him — might pass away any day now, or end up with a stroke or some other severe neurological damage that the rejuvenation process couldn’t repair.

As Don had learned on the web, a company called Rejuvenex held the key patents for rollback technology, and pretty much could set whatever price they felt would give their stock-holders the best return. Surprisingly, in the almost two years the procedure had been commercially available, fewer than a third of all rollbacks had been for men and women as old as or older than he and Sarah — and over a dozen had been performed on people in their forties, who had presumably panicked at the sight of their first gray hairs and had had a few spare billion lying around.

Don had read that the very first biotech company devoted to trying to reverse human aging had been Michael West’s Geron, founded in 1992. It had been located in Houston, which made sense at the time: its initial venture capital had come from a bunch of rich Texas oilmen eager for the one thing their fortunes couldn’t yet buy.

But oil was so last millennium. Today’s biggest concentration of billionaires was in Chicago, where the nascent cold-fusion industry, spun off from Fermilab, was centered, and so Rejuvenex was based there. Carl had accompanied Don and Sarah on the trip to Chicago. He was still dubious, and wanted to make sure his parents were properly looked after.

Neither Don nor Sarah had ever been to a private hospital before; such things were all but unheard of in Canada. Their country had no private universities, either, for that matter, something Sarah was quite passionate about; both education and health care should be public concerns, she often said. Still, some of their better-off friends had been known to bypass the occasional queues for procedures at Canadian hospitals and had reported back about luxurious facilities that catered to the rich south of the border.

But Rejuvenex’s clients were a breed apart. Not even movie stars (Don’s usual benchmark for superwealth) could afford their process, and the opulence of the Rejuvenex compound was beyond belief. The public areas put the finest hotels to shame; the labs and medical facilities seemed more high-tech than even what Don had seen in the recent science-fiction films his grandson Percy kept showing him.

The rollback procedure started with a full-body scan, cataloging problems that would have to be corrected: damaged joints, partially clogged arteries, and more.

Those that weren’t immediately life-threatening would be addressed in a round of surgeries after the rejuvenation was complete; those that required attention right now were dealt with at once.

Sarah needed a new hip and repairs to both knee joints, plus a full-skeletal calcium infusion; all that would wait until after the rejuvenation. Don, meanwhile, really could use a new kidney — one of his was almost nonfunctional — but once he was rejuvenated, they’d clone one for him from his own cells and swap it in. He’d also need new lenses in his eyes, a new prostate, and on and on; it made him think of the kind of shopping list Dr. Frankenstein used to give Igor.

Using a combination of laparoscopic techniques, nanotech robotic drones injected into their bloodstreams, and traditional scalpel work, the urgent structural repairs were done in nineteen hours of surgery for Sarah and sixteen for Don. It was the sort of tune-up that doctors normally didn’t recommend for people as old as they were, since the stress of the operations could outweigh the benefits, and, indeed, they were told that there had been a few touch-and-go moments while work was done on one of Sarah’s heart valves, but in the end they came through the various surgeries reasonably well.

Just that would have cost a fortune — and Don and Sarah’s provincial health plan didn’t cover elective procedures performed in the States — but it was nothing compared to the actual gene therapies, which required the DNA in each of their bodies’ trillions of somatic cells to be repaired. Lengthening the telomeres was a key part of it, but so much more had to be done: each DNA copy had to be checked for errors that had intruded during previous copying, and when they were found — and there were billions of such errors in an elderly human — they had to be fixed by rewriting the strands nucleotide by nucleotide, a delicate and complex process to perform within living cells. Then free radicals had to be bound up and flushed away, regulatory sequences reset, and on and on, a hundred procedures, each one repairing some form of damage.