“Five days later (Earth-time, naturally—this garnet doesn’t cover comparative chronology) he was back, with a slip from the foreman: his efficiency was low and he was too cheerful about failures. What was the matter? The medic gestured again with the gauge, found no fever—on the contrary the man’s body temperature was several degrees on the safe side—and referred him to the disciplinary squad.
“Three more days passed. A friend brought the victim in this time. It was impossible to rouse him sufficiently for useful performance. The man was in an amiable stupor, and it was known that he had drunk no bootleg in two days. He no longer ate at all. And as long as he was here, the friend mentioned, he’d felt cold for a moment himself, a couple of days ago. As though a cold wash of air had descended on him, making him shiver, though no one else had felt it. It had passed in a minute and he felt fine now, better than ever, as a matter of fact, but… The medic automatically played the gauge over him, found no fever, dismissed him, made another entry in the record (for he was a good medic), and took the slack laborer in charge.
The man’s body temperature was 297°K and dropping. This was an unusual departure from the human norm of about 310°K, and the medic was intrigued. The man had no symptoms that could not be accounted for by the chill itself; what caused the chill was a mystery. In due course the patient died and the fact was properly noted. A report was sent routinely to Earth where it was lost in clerical tape and forgotten.
“Meanwhile three more men, including the friend, were down with it. They were not sick—that is, they had no fever—but the medic, catching a glimmer of a problem requiring a technique for which he was not competent—that is, serious thought—held two for observation and shipped the third directly to Earth for study. That one was intercepted by the efficient quarantine station and retained for proper dispensation. He was dead by the time the medic Officer of the Day had been notified, but Standard Operating Procedure had been upheld to the letter of the death certificate. Autopsy revealed the cause: malfunction of vital tissues owing to insufficient temperature. The body’s natural regulatory mechanism had lapsed. No cause for that had been determined.
“A month later over half of the colony’s 2,000 person complement was dead, and more were dying. The planet was quarantined. Earth shipped supply capsules, charging their cost against the colony’s Earthside performance bond, but refused to accept any person or anything from the settlement itself. Thirty-six days after the onset—officially fixed at the moment of the first victim’s initial shakes—ten additional men and women suffered the warning siege and set their affairs in order, each in the manner befitting himself and his religion. On the following day no new cases were reported; nor were any on the days thereafter. The ten recovered, and the epidemic (for so it was then regarded) was over, as mysteriously as it had commenced. The colony was held in quarantine for five years, during which time it accumulated a debt it would take a century to exonerate, but there was no recurrence, either there or anywhere else.
“Fifteen years later the chill broke out again, however, at a colony twenty-five light-years distant from the first. The pattern was identical, with the exception that the authorities alertly slapped on the quarantine within hours of the first death. Half the pioneers had been fatally infected within thirty-six days; the rest lived. Humanity breathed a collective sigh of relief when no contagion was detected.
“Now the debate of the first century § raged hotly over the chill. What was it? How did it spread? For the first question there was no satisfactory answer. For the second there were several. One vociferous group held that the chill propagated by etheric waves traveling at the speed of light, a kind of death ray engulfing entire planets and moving on after a suitable interval to others. This was quickly labeled the Wave theory. Another leading group claimed that the contamination spread by personal contact, transmitted by some short-lived virus that rapidly mutated into impotence: specifically in thirty-six days. This was known as the Particle theory.
“The Wavists were challenged to demonstrate just how a wave traveling at lightspeed could traverse twenty-five lightyears in just twenty years. But they rationalized that the inclining beam emanated from some third point, twenty years closer to the first afflicted colony than to the second. They waited eagerly for a third colony to be struck, so that triangulation could locate the origin. And in turn they challenged the Particlists to explain why no member of the moon-based quarantine party had contracted the illness, since many had been exposed before the full danger was understood. And why the chill showed no abatement whatever prior to its fixed termination, if it were really mutating its steady way into oblivion. The reply was that the quarantine experts had been exceedingly careful at all times, as proven by their ability to avoid contagion by the chill; and that the chill itself abated even though the symptoms displayed by man did not. When the causative virus weakened so that it dropped below the threshold of effectiveness, the body’s natural defenses were able to repel it.
“Five years later both theories had their trials. A third colony was struck—but because its medic had been too busy publishing the learned tracts required for tenure and promotion to keep up with the medical literature, he failed to recognize the chill until several deaths had occurred. Infected colonists by this time had visited five other planets, including Earth itself. Moon station had been bypassed. Yet not a single case appeared outside the stricken colony, though the sick travelers cooled and died in public hospitals. The Particlists strained to explain the paradoxes, and could not. One of the victims had happened to be a popular call girl who continued her practice until her clientele complained of her literal frigidity. She died; the clients lived. The particle theory had been exploded.
“The Wavists pounced on the third coordinate with enthusiasm and triangulated for the fabled source. The third point was seventy-three light-years from the first; location was elementary. A ship of experts was dispatched. It found only empty space. If there had been a source, it had departed long since. And the disgruntled Particlists were quick to point out that a number of unaffected colonies lay between that so-called source point and the affected planets. How had those other colonies been missed? Was the wave discriminating? But in any event, the particular beam to strike the third colony could now be extrapolated. Volunteers planted themselves squarely in it—and were not affected. There was no beam, and the Wavists had been swamped.
“Time passed and the mystery deepened. Additional colonies were devastated, yet any victim removed within a day of the first symptom recovered promptly. If the chill were a contagious disease, why did time and location set such capricious limits? If it were a wave, why did so many escape?
“Gradually the unwilling answers appeared. Compromise gained the day. The chill did travel in lightspeed wave formation—but that wave was neither singular nor local. There were many waves, approximately a light-month in depth and ninety-eight light-years apart. The intersection of any wave with any colony meant pandemic until it passed. But within that wave there seemed to be random particles of infection that struck solely by the law of averages. Presumably there was a nutrient ether that guaranteed the progress of the illness unless the victim was promptly removed from its field. As with the ether of yore, none of this was detectable by instrument of man. He understood its presence by dying.