Alan E. Nourse - The Fourth Horseman (9 page)

With a conscious effort he pushed the Seattle cases aside in his mind and went back to Pamela Tate again, to the little snag in that story, the place where the circle didn't quite close.

It was the timing. It was too fast. Carlos had remarked on that before he took off for Denver—it was all far too fast. It didn't fit the classical picture of plague.
Unless there is something else very unclassical involved . . .

He sat back, letting his mind wander for a moment. If it didn't fit the classical rules, it did fit, in a way, Ted Betten-dorf's own private concept of this ancient and terrible disease. His personal picture, unproven but perfectly reasonable, evolved from his own long years of studying and writing about the
pestis.
Only now the microbiologists and geneticists were coming up with exactly the pieces he needed to fill the holes in his picture, the missing pieces that had hung up the progress of the scholarly work he had been writing, the thick bundles of manuscript piled on the shelves behind him. . . .

Pamela Tate was only one of multimillions that this ugly Thing, this pestilential disease, had slaughtered down through the ages in its murderous fight for survival on Planet Earth. She was not even the first in modern times to be struck down. But just suppose, Ted reflected, that she really
were
the first human being to suffer the effects of some slight change in an ancient pattern of survival, some tiny interior genetic change in the organism, almost undetectable, occurring by blind chance, triggered by the natural radiation in the earth, or some happenstance direct-hit by a cosmic ray, or just by the organism's natural tendency to shift its genetic arrangement spontaneously. Suppose that somehow, for some reason or no reason, three tiny amino acid fragments on a certain spiral of DNA had gotten displaced, maybe traded places with three different amino acid fragments, while three others dropped off altogether, and the change somehow improved the survival qualities of that one organism over its brothers, led to slightly different infective qualities given precisely the right host—and suppose the change was then passed on to successive generations. It could be so simple, and so deadly. A minor step in an evolutionary chain that made one organism and all its progeny subtly and horribly more capable of survival—and murder. The organism wouldn't know or care—it couldn't, for it had no sentience. All it had was an implacable, mindless need to survive. . . .

Ted ran a hand through his thick gray hair and pursed his lips. Sheer speculation, of course, but the notion was sobering—and from his own studies, he was convinced there was supporting evidence from history. One thing was certain: the organism of plague was a tough survivor from way back. Nobody knew when it had first made its appearance on earth-surely long before the beginning of recorded history. Probably it had evolved geological ages ago in the warm, salty seas at the same time that other one-celled creatures first appeared. Maybe many bacteria evolved at the same time—nobody knew for sure. But unlike other free-living, motile protozoan water creatures, unlike the algae and
Euglena
and diatoms and other free-living one-celled plants, the bacteria were never free, complete forms of plant life. They were always cripples. They needed help. They mostly depended on decay for their nourishment. Many became useful symbiotes with other life forms: they released nutrients and fixed nitrogen from dead matter for plants and animals to use. They fermented rock into sand and then soil so that the land plants and aninials could survive. They were the garbage men of the planet, busy seeing that nothing was wasted in the great cycle of evolving life.

Many were benign and helpful, but not all. Some attacked and destroyed living things—and these survived along with all the rest, tiny capsules of death, crippled and malignant half-cells. They too grew and evolved, Ted thought, and now millions of years later they were still picking their hosts, their favorite victims, destroying life in order to survive, and creating jobs for people like him. . . .

From the best accounts he knew, that ugly Thing that had slaughtered Pamela Tate first made its appearance in recorded human history in the ancient city of Athens in 753
b.c.
One day in that unhappy year, without warning, people in a great and civilized city began dying. Many people, and many rats. No one then saw any connection. For the people, the dying was horrible: fever, prostration, great purple-black welts appearing under the skin, huge festering painful lumps of swollen flesh appearing in the armpits and neck and groin and finally, after days of agony, a death that must have been a welcome relief. They called it "The Pestilence" or "The Death" in those days, and if The Pestilence was really caused by angry gods, as the people believed, the gods must have been appeased because The Death finally went away. And none too soon, either. Ten thousand people died in that wave of Death, and since the mighty Athens of those days probably had no more than thirty thousand inhabitants, as much as a third of the population was wiped out. Another third suffered the infection and recovered. Including, of course, some of the rats. And the fleas that fed upon the rats.

Whatever the exact numbers—they varied with the source, Ted knew—The Pestilence had vanished as suddenly as it had come, and remained quiescent for centuries. It was next recorded in Rome in
a.d. 103.
It was Rome at the height of its glory, a city of 1.5 million people, largest of all cities of the ancient world. The Rome of those days was remembered down through history for its excellent supply of pure water, and its fine sewers for the disposal of human waste. But for garbage disposal and other matters of everyday hygiene, Ted reflected, not so much could be said. The common man of Rome in those days lived in filth, along with the rats. Even the kitchens of the nobles were filthy and rat-ridden.

When the disease struck Rome, perhaps the same disease of Athens; perhaps something slightly different, it stmck with ferocious violence, devouring five thousand human lives a day. The sheer logistics of disposing of all those corpses in that huge city must have been staggering in itself. And the death toll went on for months, perhaps years, no two accounts agreed. Then, once again, it stopped for a while—but by that time another name had been coined for the murderer. A name that said it all:
The Plague.

It recurred repeatedly in parts of Italy in succeeding centuries. With the fall of Rome, records became obscure. In the tenth and eleventh centuries Italian coastal cities recognized that the dread death-dealer often arrived by ship. Boats were required to hold offshore for a
quarantine
—a period of forty days—before anybody or anything was allowed to come ashore; as a result, some of those cities escaped The Death.

Despite all this, in the 1300s, The Plague struck hard and fast in Mediterranean regions and began moving inexorably north and west in a long, slow, murderous sweep across Europe and Asia. In those days, in the very depths of the Dark Ages, there, were few cities large enough to speak of. Most people lived in villages and hamlets clustered around the manor houses or castles of local lords for protection. Nobody had the slightest concept of personal cleanliness or public hygiene. "Lest one think it a romantic time to have lived," Ted had once told a lecture audience, "bear in mind that everyone had lice and everyone had fleas—rats, dogs, cats and humans. The average life expectancy for a new baby in those days was about thirty years." As The Plague struck these villages, one by one, the widely rumored symptoms began appearing: fever, shock, huge black draining sores in the neck and groin, followed by convulsions and death, or—in some cases—a long, painful convalescence leading to recovery. No patterns of spread were recognized; people accused the physicians of the day of spreading the disease in order to fatten their purses, despite the fact that they were dying faster than the patients they tended. And in that great epidemic, a new twist seemed to appear: some victims, after a few days of illness, suddenly began burning up with fever, coughing fiercely and hemorrhaging from the lung. This so-called "pneumonic" form of The Plague terminated in death within two or three days and killed as many as eighty-five percent of its victims—and, for the first time, direct spread of infection from one person to another was clearly recognized.

Of course The Plague spread panic wherever it struck. People boarded themselves up in their houses to keep it out—and died inside. Bodies of the dead were stacked like cordwood at the crossroads to be bumed or just left to fester and decompose. The stench of rotting bodies clung over whole villages. Dwellers in castles and fortresses pulled up their drawbridges to protect themselves from the horror outside, only to be found, sometimes years later, all dead
inside
the walls, mostly from Plague, but many from starvation or thirst because people were too terrified to come out. Certainly in those superstitious days The Death was considered the work of Satan, but the spread of the disease was slow and sporadic. Nobody traveled very far or fast in those days, and the march of The Pestilence was measured in years as first one village was hit, then another. Some were missed altogether by some stroke of fantastic good luck; others were wiped out almost totally. The slow march of Plague across the continent took 150 years or more that time, and when it was all over, it had proved to be the most vicious Pestilence in all human history, leaving some twenty-four million people dead in its wake—one-quarter of the entire population of Europe.

Slow as it was, that great Plague had been more virulent, more deadly, than any that had preceded it. All the accounts and records Ted had ever read confirmed that. But why? Had there been some tiny, seemingly insignificant genetic change then, too? Some rearrangement of atoms on a strand of DNA? No way to tell, of course, but earlier plagues, horrible as they were, had been a laugh compared to what that one had been.

Finally it had seemed to burn itself out, reappearing only sporadically, here and there, over the next two hundred years. Then, abruptly, London was struck in 1665—that crowded, huddled, jam-packed, filthy city of 500,000, built on the banks of the oily Thames with its piers and docks and warehouses and rats and fleas. Plague swept the city then like a giant scythe— sixty-eight thousand dead in a single year. The following year a sort of Providence intervened: the Great London Fire gutted four-fifths of the city, burning out millions of rats and their breeding places at the same time. It was an awful remedy—but never again was there a major outbreak of plague in that city.

Just over two hundred years later, in 1894, Hong Kong was struck with epidemic Plague. Things had changed during those two hundred years, Ted reflected. The concept of scientific observation had emerged, and now it was known that rats and Plague were inextricably interrelated. Get rid of the rats and The Plague slowed and stopped. Bacteria had been discovered, and were known to cause infectious diseases of all kinds. Though the organism that caused Plague had not yet been isolated or observed, it was assumed to exist, and was given a name:
Pasteurella pestis
after the great French pioneer of microbiology, Louis Pasteur. Then in 1894 two different men—a Japanese named Shibasaburo Kitazato, and a Swiss, Alexandre Emile Yersin, separately isolated a slender, poorly staining rodlike bacillus from blood and tissue of Plague victims— the organism causing The Plague. Ultimately its name was changed to
Yersinia pestis.

Identifying the ancient killer did not stop it, however. In the late 1890s it swept from Hong Kong to the cities and opium dens and brothels of the South China Coast—Canton, Foo-chow, Shanghai—killing fifteen million people. It moved south across tropical Asia—Singapore, Bangkok, Rangoon—and plunged into India, where ten million people died in a single year. And in Bombay, amid festering heaps of dead bodies, another obscure scientist finally closed the link of causation.
Yersinia pestis
was primarily a disease of rats, afflicting the ubiquitous black Norway rat in particular, but other rodents as well. Fleas living on an infected rat drank its infected blood; when the rat died, the fleas abandoned the corpse, found another rat and injected their bacteria-laden vomit into the new victim when they bit. And when rats weren't handy as a new host, those infected fleas found humans instead, and the humans grew feverish and shocky, with huge festering buboes developing in their armpits and neck and groin, and developed massive purple skin hemorrhages as the infection progressed to septicemia, or coughed blood as it reached the lung. And when they died, their infected fleas went on to bite other humans.

Fortunately, there were no airplanes in 1894,
Ted Betten-dorf thought. If there had been, that vast pandemic of Plague might never have been stopped. Ships were far slower, with far fewer ports of call. Ships from Hong Kong brought The Plague from the Far East to Philadelphia, New York and San Francisco, especially San Francisco. Public health measures stopped it at the docks in each of those places, but plague-bearing rats abandoned ship all the same. Some of those rats, unwelcome in the city, made their way into the hills and forests surrounding San Francisco, and then to the Sierra Nevada, their fleas infecting forest rodents as they went—chipmunks, ground squirrels, marmots. A reservoir of plague-in-waiting built up in those creatures, far from human habitation, a reservoir of "sylvan plague" which slowly, slowly spread north to the Cascades and east to the Rockies, and south through the Sangre de Cristos.

From then on, a few cases of human plague had begun to appear in the western United States each year. Isolated cases,
a
dozen or so one year, three or four the next. Year by year,
Ted
Bettendorfs section on Uncommon Diseases at the Centers
for
Disease Control, a branch of the United States Public Health Service, monitored those cases, kept a watchful eye on them, ever alert to the subsurface danger that existed. A child playing with a sick chipmunk on a California camping trip. A Mexican woman near Nogales living in a house infested with rats. Two boys in New Mexico cutting off the flea-ridden pelt of a dead coyote they found in the hills. The cases were sporadic, individual, almost always related to rats, rodents or fleas. Often diagnosed far too late, and veiy deadly—three-quarters of those victims died. But slow-moving, never really catching fire.
Over the years,
Ted thought,
we've been lucky. That Horseman, called Death, has been in no hurry.