"We've developed a self-replicating nanotech device, somewhat like an artificial stem cell," the doctor explained. "We've tested it on a wide range of injuries and debilitating conditions, all with astounding success. What we need now are some healthy test subjects so we can eventually get an idea of the N-Cell's suitability as a preventative treatment."
"To prevent what, exactly?" Jon asked.
"Aah, that's the 60 billion-dollar question. What it does is build up a pervasive low-level permanent presence in your whole body. Then, if anything should happen to you, the N-Cells will help heal you quickly. Regenerate, even. In most cases they should be able to do this using mostly your own cells, but if for whatever reason your natural tissue can't keep up, the N-Cells can pick up any slack and imitate whatever type of cell your body might need."
"So, in other words, this stuff is supposed to make me what-- immortal?" Jon asked, pretending to be incredulous.
"We don't like to say that," the doctor said. "Mostly because that's not what we were trying to achieve at first, and because it would take a whole lot more observation to say anything conclusive about that. But as far as we can tell, the N-Cells can reverse and keep in check the effects of old age, and considering all their capabilities together, I can not say with any certainty at all that the N-Cells are not possibly what you suggest it is. For one thing, how old do you think I am?"
"You look about fifty or so," Jon guessed. The doctor's hair was nearly white but otherwise he didn't seem all that much wrinkled.
"Actually I'm closer to ninety. And yes, of course I've taken the N-Cells myself. Anyway, shall we move on?"
Jon and Karyn were led to separate rooms where they signed some forms. Minutes later, someone stuck each of them in the arm with a syringe.
"That's it?" Karyn asked.
"Pretty much, and as a neat side effect the hole from the shot should be closing up right away," said the lab assistant who had stuck Karyn.
Karyn took a look at her arm and couldn't even find the wound. "Cool. Just a tiny bit sore."
Karyn came out and rejoined Jon at the doctor's office.
"The non-disclosure agreements you signed will remain binding for one year, after which point we will attempt to go public," explained the doctor. "Here is a list of your scheduled lab visits for the next year." He handed Jon and Karyn each a few stapled sheets. "Any questions before we take you back home?"
Jon read over what he had been given, and thought for a minute. "Just one thing. What happens when these N-cells replace the whole body?"
"Who can say? No patient has gotten to that point yet. But one thing that does happen in patients in an advanced stage of N-cell symbiosis is that in localized parts of the body, some of the N-cells will de-differentiate. We think that this is what would happen to the whole body if something happened for the N-Cells to take over that many bodily functions. Basically, it is possible that some day you will decompose into a blob of goo, to put it crudely. But that would not likely be any sooner than you would normally die of old age, and the opinions are divided as to whether this eventuality is in fact deadly."
"Interesting. I guess, considering everything, I didn't make a mistake in signing up for this, Doctor..." Jon paused, realizing he never learned the doctor's name.
"Chester. I'll see you around, then." The doctor shook Jon and Karyn's hands, and sent them on their way.
The next day, Jon took advantage of the weekend to visit Karyn for a while longer.
