“No.” O’Donnel thought a moment. “Y’know, it’s strange. We were tired and hungry and scared that we wouldn’t make it all the time we were in the jungle, but in some ways it was really neat. Maybe it was just that there was more oxygen at a higher pressure than I’m used to. But all my life I’ve been told how awful and dangerous the jungle was, but when we were there it was, well, pretty.
“I’d like to go back sometime.”
“Maybe,” Rey said, “but only after you are completely recovered.” Lots of luck getting permission from the Committee on Colonial Security. “In the meantime, I’d like to run more tests. This will mean getting poked and prodded, and submitting to the additional indignities of giving blood and stool samples.”
“You make it sound irresistible,” O’Donnel muttered.
“On the other hand, we may be able to learn something from you and your friends that will save lives in the future.”
O’Donnel rolled his eyes to the ceiling with a sigh. “Let’s get on with it, then.”
The answer came early that evening. He had sealed his samples into their small plastic dishes and placed the dishes in the trays of the automated microscopes, there to be cared for by the medical AI programs until he could make time to conduct an examination.
An alarm went off. It was a soft-spoken, almost deferential alarm. Instead of screaming a strident warning, it seemed to say “Take a look over here; this may interest you.” What it most likely meant was equipment failure or a mistake in programming parameters.
“Computer: alarm visuals, please.” Then he kicked himself mentally as he remembered that voice activation was one of the many frills the clinic did without. Muttering, he punched in the proper command.
The screen glowed to life. Strange shapes moved like shadows, elongating, their trifurcated ends grasping for nourishment, then curling up into balls for no apparent reason.
“What the hell?” His tone was almost reverent. He tapped a series of keys.
ACCESING MICROORGANISM DATABASE.
Twenty seconds elapsed, no match FOUND.
“That’s what I thought.” Another series of commands established a satellite link to the Terraces.
“Security authorization.” The voice was tired and more than slightly irritated.
Rey frowned. “Since when does a colony clinic need a security clearance to access a medical database? I thought that was what our taxes were for.”
“Who—? Is that you, Rey? How are things on the frontier?”
“Mongosuthu?” Rey guessed. “You used to have a real job as a researcher. What’s going on back there?”
“Things are even crazier than usual,” Mongosuthu grumbled. “Natu-ralers got into a lot of the systems two weeks ago, looking for evidence of some grand conspiracy to suppress ‘the Truth,’ whatever that might be. Colonial Security had a fit, thinking they might crash the databases. My part-time job as gatekeeper is one of the results.
“Here’s what we do. When you hear someone request your authorization, you say ‘Medical priority.’ Say that now a few times, so we can put your voiceprint into memory.”
Rey did so.
“Good. Try to sound as natural as you can when you call in. The program is supposed to evaluate stress in case you’re being coerced. So far it’s shut out three docs calling in for emergency support.
“Now that that’s all taken care of, what can I do for you?”
“I have some beasties for you to look at,” Rey said. “They are not in the standard references.” He keyed in the visual from the microscope.
“Hmm. Bizarre looking,” Mongosuthu said. “Where do they come from?”
“The intestines of one of my patients.”
“Any symptoms?”
“None I can be sure of. He was in the jungle for a couple of weeks, and is about as tired and exhausted as you might suppose.”
“Ah! So this is one of the missing rock climbers. Wait—” Five seconds elapsed. “The AI diagnostic suggest some sort of parasite. No match in the records, though. Those trifurcations are a pretty dammed distinctive morphology. If it were anything terrestrial, it should be in the database. But if it’s native, it shouldn’t be able to exist in a human gut. Any idea how he became infected?”
“He says they ate some of the native plants,” Rey said.
“Well, that explains it. Your boy ingested some of the local fauna, which not only came with assorted bugs, but also created an intestinal microhabitation which was not immediately fatal. He’s lucky it didn’t kill him.”
“I’ve already told him that,” Rey agreed.
Rey readied himself for bed, mind awhirl with thoughts which went nowhere but would not settle down. He pulled the sheets up, enjoying the scents which had permeated them as they hung outside to dry. He took a deep breath and let it out slowly, reveling in the simple act of breathing.
And stopped. He had left a breathing mask high in a tree more than three days earlier. In the excitement, he had forgotten to unwrap a replacement. He had even forgotten his antihistamines. And never in his life had he breathed so easily.
He sat up, suddenly wide awake.
“Mind telling me just what the hell you’re doing?” Marty asked sleepily. It had been her night to sleep in the clinic, in order to take emergency calls. Rey had tried to move around quiedy, but obviously he had not been quiet enough.
“Research,” he said. “I got an unexpected lead on why nobody here has allergies.”
“Really?” Martina asked skeptically. “Like what?”
“Like I suddenly remembered an old theory that allergies were the result of an underworked immune system. Take a look at that first screen.”
“I see it,” Marty said. “What is it?”
“You are looking at a stool sample from O’Donnel. The things you see wriggling around have been tentatively identified as native parasites, though they aren’t on any database. Now, it’s an odd thing, but the archives note that back on old Earth, human population that was infected with any of the local parasites rarely if ever suffered from allergies. That was a disease of what you might call the overly-hygienic. The theory was that a substantial part of the human immune system had evolved to deal with parasites, and that when they were absent, the system went into overdrive, reacting against basically harmless dust and pollen particles.
“Conversely, if parasites were present, allergies would disappear.”
Marty sat down heavily on a stool and blearily regarded the monitors. “Excuse me for being dense this late at night. Or this early in the morning. But doesn’t it occur to you that whatever your explanation does for O’Donnel and his friends, it has no relevance to the rest of us?”
“Take a look at the second screen,” Rey suggested. “How would you say it differs from the first?”
She squinted uncertainly from monitor to monitor. “Not at all that I can see.”
“That second screen is from a sample I provided,” Rey said. “I’m willing to bet that everyone on Far Edge is infected.”
VI.
Six days later, Rey woke to learn that the Committee on Colonial Security had placed Far Edge under interdict. Neither people nor goods would be allowed into or out of the colony.
“Big deal,” he muttered at the breakfast table. “There hasn’t been any contact to speak of with the other colonies since I came here.”
Ryn-Rosenberger frowned. “The winter winds should cease by the end of the month. We need the zeps for heavy machinery, for new satellite dishes and fiber-optic cable. For that matter, do you plan on culturing your own drugs when you run out of your current supply?”
Rey grimaced, acknowledging the sense of that statement. He shoveled food into his mouth, resolving to wake up more fully before taking the next opportunity to make a fool of himself.