THE JUNGLE IS SO THICK THAT ARTHUR Demarest and the archeological inspector assigned to him don't see the army platoon until the comandante is in their path, demanding identification. Demarest has plenty: documents from Guatemala's History and Anthropology Institute, a gold-sealed letter from National Geographic and even a notarized Spanish translation of his Harvard diploma. The comandante , whose squadron of full-blooded Mayan Indians appears ominously battle-scarred, offers to lead them to the cave they're seeking--not exactly the safest proposition in this guerrilla-infested rain forest, but unavoidable under the circumstances.
For three hours they follow their machete-wielding guides through the amber-green filtered light of the mahogany canopy, their eyes probing the leafy ground cover for venomous serpents while scarlet macaws screech overhead. Finally they arrive at a large hole in the moist soil, leading into a limestone cave. As they descend, their lamps reveal a stretch of stalactites, an altar black with burned incense, human bones painted red, ceramic pottery, lithic spear points and a cascading stream. There is a noise, and something shoots past them; a large tropical rodent called a tepezquintle , a local delicacy. Immediately, soldiers aim their automatic M-16s, and everyone screams. The inspector drops his camera, breaking it, and Demarest pleads with the comandante to stop the firing; pots will be trampled, ricocheting bullets will kill them all, the cave will collapse--and with it his hopes of answering the question he is spending more than $1 million to answer. Eventually, the rodent disappears, the soldiers hold their fire, and the archeologist, the inspector and the artifacts escape unscathed.
IT IS ONE OF HISTORY'S GREAT MYSTERIES.
No one knows for certain where they came from. As for when they arrived in Central America, less is presumed now than 20 years ago, because the dating of early relics at 2500 BC hinged on faulty carbon-14 data. Assumptions abruptly dissolved, leaving the truth buried beneath more than two millennia's worth of jungle and alluvium. It is generally agreed, however, that by 900 BC a sophisticated culture called Maya had spread across the great lowland limestone shelf that today comprises Mexico's Yucatan peninsula, Belize and the northern half of Guatemala.
It was an elaborate society that must have seemed to its people destined to thrive forever. Sixteen-hundred years later, at least 6 million Maya lived in what in some ways resembled Southern California: a flourishing megalopolis of city-states, with few breaks among their overlapping suburbs. Their monumental architecture, as well as their painting, astronomy, mathematics and literature, humbled the achievements of their contemporaries in Europe. Equally striking and far less understood is how so many could inhabit a tropical rain forest. For centuries, they raised their food and families in the same fragile environment that today is quickly devastated by a relatively few hungry squatters.
What has baffled archeologists even more, however, is the Maya's spectacular, sudden collapse. Within just 100 years at the beginning of the 8th Century, lowland Mayan civilization simply vanished. In most of the Yucatan, only scattered remnants of the population remained; the Peten province that encompasses northern Guatemala was left virtually uninhabited. Rain-forest vegetation soon overran the ball courts and plazas, enshrouding tall pyramids. Except for an occasional vagrant Spanish conquistador, not until the 19th Century would the world again be aware of the Maya's existence.
Speculation over what happened to the Maya has included possibilities such as famine, epidemics, overpopulation and soil erosion--yet for each explanation, arguments exist against its causing extinction on such a massive scale. Although most Mayan cities were notably indefensible, no relics indicate a significant invasion of alien forces. Often extolled as history's exemplary peaceful society, the Maya seemed least likely to consume themselves in internal warfare. Yet Demarest's recent discoveries in the steamy Peten suggest that is exactly what happened.