Serpent

approximate but fairly accurate sun's azimuth.'

'What are the other wheels used for?'

'They could be a can opener for all I know You'll have to ask someone with technical expertise;' Gamay said with a shake of her head. 'Too bad the mechanism is corroded. I wouldn't mind knowing where we are..'

Chi rummaged in his rucksack and pulled out a map which he spread on his knees. 'This river isn't shown,' he said, tracing their approximate route with his finger. 'My guess is it's only this big after rainy season. When we factor in our direction and speed, I'd venture that if we haven't gone over the border to Guatemala, we're very close to it. Which would make sense. The looted artifacts are smuggled through Guatemala. to Belize and points beyond.'

'I wasn't planning on a trip to Guatemala when I came down here for NUMA, but I guess I don't have much choice.'

'Look on the bright side,' Chi said. 'We have the chance to put a stop to this terrible business of smuggling antiquities.'

Gamay cocked an eyebrow. She hoped some of Chi's optimism would rub off. Given the precarious state of their minute-to-minute existence, she hadn't thought of them as a smugglerbusting duo. Her main goal was survival. She was getting tired of playing the Perils of Pauline. The fact that they weren't dead was probably mostly a result of dumb luck.

She indicated several penciled X's on the map. Any idea what these are?'

After a moment's study Chi said, 'They could be anything. Dig sites, places they stockpiled artifacts or supplies, distribution.'

And we're heading right into the middle of things from what this handydandy device tells us.' She hefted the instrument and gave it back to Chi.

'Interesting,' Chi said thoughtfully as he carefully stuffed the ancient instrument into his pack. 'In our zeal to put this to practical use we have forgotten its archaeological significance.'

'I'll leave it to others to hash that out. I'm a marine biologist now.'

'Yet you can't deny that finding an ancient Greek artifact in a pre-Columbian setting raises questions.'

'Questions I'm not prepared to answer.'

'Nor am 1. Not yet. But I know that I will bring the wrath of the archaeological establishment down on my head at the slightest hint of pre-Columbian contact with Europe. This instrument did not get here by itself. It was either delivered by Europeans to America or transported by Americans who went to Europe.'

'Maybe it's a good thing we don't have anybody to tell,' Gamay said.

The strengthening current ended their discussion. The river had become even narrower and gorgelike, the walls steeper and higher. Chi was having trouble controlling the boat, and Gamay took over. There was no noisy ,rushing of water that would indicate they were near rapids, not yet, but Gamay stayed alert.

'Our speed is picking up,' she told Chi.

'Can you slow us down?' .

'I've got the motor practically on idle to maintain steering control. Keep a sharp eye and ear out. If it looks like rough water ahead I'll steer for shore, and we'll figure out what to do.'

At the foot of the walllike bankings was a muddy beach a couple of yards wide. Enough space to pull off the river for a breather. She was buoyed by another consideration. This was fine only way the chicleros could have come. Which meant the river was navigable for a small boat. Controlling the towed boat was a problem. Time to pull up on shore, transfer supplies, and cut loose.

The river suddenly narrowed considerably, and the water speed doubled.

She and Chi exchanged puzzled glances. Still no sound of rapids. They were rounding a long curve, the bankings closing in so that it seemed that they could almost touch them. Gamay planned to go wide on the turn and simply rum the boat onto the narrow beach. The supply boat whipsawed, then jerked in the other direction to throw her steering off. She knew from . experience that when things go wrong on a boat they realty go wrong. Drastic action is the only way to avoid disaster.

'Cut her loose!' she shouted.

Chi stared at her, uncomprehending.

She made a knifing motion with the edge of her hand. 'Cut the supply boat line, or it will tangle in our propeller.'

Once Chi understood he acted quickly. He severed the towline with a quick swipe of his machete. The loaded pram went into a slow spin and headed right at them. Gamay and Chi were both watching the boat, hoping it would pass them. A collision in the narrow canyon would be a disaster. She was glancing over her shoulder, trying to steer so as to avoid a crash, and didn't see the wall of limestone that loomed directly in their path until the last second.

Gamay ducked so she wouldn't hit her head as the pram shot through an opening in the wall. Within seconds the swiftmoving river had sucked them deep into the maw, and the vestiges of daylight disappeared.

'We need a flashlight, Professor,' she said, her voice echoing in the inky darkness.

The flashlight flicked on, and the shaft of light fell on wet rocks that glistened only yards away She swung the tiller to avoid a crash, oversteering in her haste, and was turned sideways by the current. After a few dicey moments she had the boat under control again and was moving with the river flow.

Chi played the flashlight beam ahead and above on rough wet walls and ceilings. The underground river reminded Gamay of a fun house, only she wasn't having any fun. Especially after the beam picked up what looked like clusters of black leaves covering the ceiling. The light reflected on thousands of burning-red pinpoints of light. She held her breath not so much out of fear but to block out the overpowering ammonia stench.

'I hate bats,' she muttered, gritting her teeth.

'Keep still, and you'll be all right,' Chi cautioned.

No need for that warning. Gamay was frozen in place by the thought of leathery wings and sharp pointed teeth.

The creatures stayed where they were, however, and in time the bat population thinned out to nothing.

'Fascinating,' Chi said. 'I've never seen a river go underground so abruptly.'

'Excuse me for saying so, Professor Chi, but your country has too many caves and holes in the ground for my taste.'

'Si, Dr. Gamay It's like Swiss cheese, I'm afraid.'

Gamay tried to look on the bright side, then realized there wasn't one. They had been sucked into the bowels of the earth, and there was no assurance they would ever come out. At best, this was the route the chicleros used, which meant they might bump into more of the smugglers. Gamay lifted the propeller out of the water, and they used a paddle to steer, fending off with their hands and feet when the pram bumped noisily into the sides of the cave.

Gamay grabbed on to a small stalagmite and wrapped a few turns of their severed tow line around it. The makeshift cleat held. They crawled up onto a rock shelf and lit a camp light. Gamay expected their errant supply boat to come barreling by but it must have been caught up. Chi mourned the loss of his Spam. Gamay said maybe they would catch up with it later. She wouldn't miss the canned meat, but the fuel and water would come in handy.

Over lunch of jerky and cold tortillas they discussed their options and agreed that there was only one: they had to go on. Neither expressed the unspoken fear that the river would come to a dead end. Or no end at all. But the possibility hung over their heads like a black cloud.

They got back in the boat, restarted the motor so they'd have control and traveled another half hour, often bending over with fits of coughing from the damp musty air. Gamay felt as if her lung linings were becoming as mildewed as the rest of her. The current seemed to diminish. Chi, who'd been lighting the way ahead, announced that the river was almost back to its original width above the rapids. Chi had placed the camp light in the prow of the boat, and its yellow glow illuminated what looked like a large cave.

'Stop!' Chi shouted over the suddenly echoing sound of the motor.

Gamay cut power and jerked the tiller around, narrowly avoiding. a collision with the black wall in their way. The river had disappeared again. It must have gone even deeper, she surmised.

They were in a large pool. A narrow tributary extended off the main waterway. For want of a better course, Gamay pointed the pram into what looked like a manmade canal.