They ate lunch in the clouds, swathed in the swirling mists that nourished a unique habitat Igor referred to as cloud forest. A clear stream ran down the side of the road, spilling over to fill the slightest depression, each pothole a thriving miniature ecology. Innumerable small waterfalls cascaded off steep slopes, nurturing wild orchids, mosses, and bromeliads.

Igor sat on a folding chair and munched a chicken wing. “There are very few places like this left on the planet. The creatures that live here, like the spectacled bear, are solitary and secretive. Even the birds are hushed.”

Carter watched Macha hunt tadpoles in a pothole. She stayed close to the land cruiser and gave no sign of wanting to wander off. They had not seen another vehicle since they’d left Paucartambo.

“What d’you think, Marjorie? Isn’t it beautiful?”

She held her sandwich in one hand and slapped at the back of her neck with the other. “Ain’t had time to look. Been too busy killing things.”

Igor did not smile. “The first mosquitoes. Scouts and outriders, come to greet you.”

“I put repellent on everywhere,” she told him, taking another swing at her neck.

“It does not matter. The more you slap on, the better the bugs will like it. They look forward to their predinner cocktails.” He walked back to the land cruiser and rummaged around inside until he emerged with a pink bottle.

“Try this. It helps some people more than others. The best defense is to wear long pants and long-sleeved shirts, two pairs each. Make sure you keep the legs of your pants tucked into your shoes.” He handed Marjorie the bottle. “Long hair is a help.”

She took the container. “You’re twenty years late with that advice.”

As they continued to descend, the road narrowed still further, until they were driving with sheer cliff to their left and an equally precipitous drop-off on their right. Mist obscured any view, for which Carter was grateful. There were no guardrails and in many places not much road.

Forty-five minutes were wasted when they met a small logging truck inching its way upward. It took that long to find a spot where the truck could pass, and there was a horrible moment when the rear right wheel of the land cruiser actually hung out over empty space, the jungle a thousand feet or more below. But the truck finally sneaked past and they continued on downward. In twelve hours of continuous driving it was the only vehicle they encountered after leaving the Andean crest.

By evening they found themselves bouncing over hills and ruts, across fast-running streams, through mud that would have swallowed the car of a driver less knowledgeable and skilled than Igor. Trees hung over the narrow road, blotting out what sunlight the pouring rain did not already obscure and making Carter feel as if they were driving down a dark green tunnel.

It was pitch-black out when, exhausted and filthy, they finally reached the tiny Indian community of Pilcopata. Even children and chickens had taken shelter from the steady downpour. Ghostly figures darted past the land cruiser’s headlights.

Igor vanished into the storm, reappeared moments later. The fact that he was drenched to the skin did not seem to bother him.

“There is an old tea plantation across the river. They keep a few beds available for the scientists and naturalists who come this way.”

“We’re gonna cross a river in this?” Carter could see Marjorie Ashwood’s lust for Inca treasure beginning to fade. “What about the car?”

“It stays here. From this point on we go by boat or on foot. You are welcome to sleep here if you prefer the backseat of the car to a dry bed with clean linen.”

Mumbling under her breath, Ashwood climbed out into the rain. Carter carefully eased the sleeping Macha into his waterproof backpack and hefted it high on his broad shoulders. Together they followed their guide’s flashlight through the darkness.

By morning the rain had stopped. The plantation’s owner hosted a surprisingly luxurious breakfast. Exotic cries from the surrounding jungle punctuated their conversation as they ate, the raucous concert dominated by the oleaginous warble of the oropendula birds.

They were on the river by eight o’clock, speeding over clear shallows in the largest dugout canoe Carter had ever seen. Set on a ridiculously long shaft, the prop of the old Evinrude engine powered them smoothly downstream. There were no seats. Ashwood and Carter made themselves as comfortable as they could atop the piles of supplies.

Igor’s chief boatman, Pierre, had appeared magically at daybreak, accompanied by a stocky mestizo porter named Christopher. Apparently Hispanic names were less than universally popular in this part of the world.

The following day Igor directed his men to pull inshore. A short hike brought them face-to-face with a large rock outcropping which was covered with drawings.

“Ancient petroglyphs,” Igor explained. Ashwood glanced around, saw that they were alone.

“Where are your people?”

“They won’t come here,” their guide explained. “Pusharo is a sacred place to them. Come and see.”

He led them around the side of the site. Beneath a protective granite overhang the rock wall was completely covered with bizarre drawings and carvings. Many had an incomplete look to them, as if the artist had given up in exhaustion or despair and moved on to another section of stone to try and realize his intention anew. Those that did look finished resembled nothing Carter or Ashwood had ever seen. They said as much.

Igor smiled. “Do not let it discourage you. Nobody knew there were any such ancient drawings down in the jungle until Padre Vincente Cenitagoya found these in 1921. There has yet to be any systematic scientific study made of them. Nothing is known of their origins or makers and they resemble nothing the Incas did. You are free to interpret what you see however you think fit.” He studied the wall.

“Myself, they speak to me of mystery and ancient days.” He touched smooth gray stone. “This here is clearly a human face, but this object next to it utterly confuses me. Many of the shapes are unrecognizable.” He moved to his left. “I call this one ‘sun-in-a-box.’ It is fun to make up interpretations for them.”

There were hundreds of drawings, seemingly scattered at random across the outcropping. The visitors were turning to leave when Ashwood suddenly stopped and pointed.

“Wait a minute! There’s one I recognize.”

Their guide’s eyebrows lifted. “You recognize it?”

“Yes. I have a drawing of it. I’m sure I do.”

Igor considered. “If that is so,” he said slowly, “then perhaps we may stumble across something of interest to you after all.” A yowl drew their attention away from the petroglyphs. Carter looked anxiously in the direction of the river.

“The people who live in this country do not eat cats,” Igor hastened to reassure him as they started back the way they’d come.

They spent the night in tents on the shore, heading up another, smaller river the next morning. While Carter was having a marvelous time, Ashwood was somewhat less than enthused. At least when they were out in the river, he pointed out to her, the bugs didn’t harry them. She was not mollified.

Igor consulted frequently with her on directions, once angling the dugout to scoot up a tributary whose existence Carter had not even suspected, so dense was the vegetation crowded along the bank. They would keep to the water for as long as possible.

It was the height of the dry season, Igor informed them. Most of the year the terrain they were currently traversing was impassable: the land impossibly boggy and muddy, the rivers wild with froth and huge trees whose root systems had been washed away by the floods.

They supplemented their supplies with fresh cat-fish and piranha, the white meat of the latter reticulate with small bones and tasting vaguely of trout. When Igor and his men jumped eagerly into the river at precisely five-fifteen every evening (when the day mosquitoes clocked out) and splashed around delightedly for ten minutes to emerge before five-thirty (when the night mosquitoes clocked in) Carter was at first reluctant to follow their example despite the temptation of a cool bath. Accumulated sweat and grime finally induced him and his companion to take the plunge. As Igor had promised, the piranhas did not bite. But their curious nibbling kept him from relaxing as he stood in the shallows and soaped himself off.

Days later when the stream had grown too narrow to navigate they beached the dugout and hefted packs. In the thick heat and cloying humidity Carter was sure that his weighed only slightly less than his thirty-six-inch T.V. back home. Macha had miraculously acquired the dimensions and mass of the jaguar they’d heard briefly the previous night. But he said nothing, nor did Ashwood. Pierre bid them goodbye. He would remain behind with the boats, awaiting their return.

By the end of the first hour Carter found himself envying the boatman. As for himself, he could think of nothing but the hotel back in Cuzco: of air-conditioning and cubed ice, of the refreshing high-pressure shower and lemon-scented bed linen. He had long since stopped slapping at the voracious insects which worried his exposed skin, relying on the dense gelatinous layer of insecticide he slathered on every morning to protect him. This it did with greatly varying degrees of efficacy. Those insects that somehow managed to bite him right through his denim jeans he could only ignore.

Igor had spoken of diseases endemic to the Infierno Verde which not only had no known cure, they had yet to be named. Carter tried very hard not to think of such things.

Instead he concentrated on the green conflagration through which they stumbled. Igor’s and Christopher’s machetes rose and fell in rhythm, excavating a path where none existed.

By late afternoon his legs were throbbing, his feet aching. When Igor announced that it was time to take a break Carter started toward a circular clearing from which rose a single small tree, intending to use it as a backrest. The guide practically tackled him from behind.

“Stay away from that.”

“Why?” Carter scanned the ground. “There’re no bugs here, no rocks.”

“Precisely.” Igor gestured at the tree. “That’s a palo santo.”

The six-inch-thick bole looked innocuous enough to Carter, and he said so.

“Look at the ground again,” Igor advised him. “See how clean it is? Not only are there no insects here, there is very little leaf litter and no young plants. Nothing living.”

Despite the heat Carter felt a chill. “So?”