"Whatever it is," Wofford grimaced, "I just wish it would stop messing with our equipment."

-2-

Ten miles to the north, Rudi Gunn walked onto the bridge wing of the gray-hulled Russian research vessel Vereshchagin and looked up at the azure sky overhead. Removing a thick pair of horn-rimmed glasses, he carefully cleaned the lenses and then peered upward again. Shaking his head, he walked back onto the bridge and muttered, "Sounds like thunder, but there's hardly a cloud in the sky."

A hearty laugh erupted at his words, flowing from a portly man with black hair and matching beard. Dr.

Alexander Sarghov resembled a circus bear, his large frame softened by a jovial demeanor and warm ebony eyes that twinkled with life. The geophysicist from the Russian Academy of Sciences Limnological Institute enjoyed a good laugh, especially if it was at the expense of his newfound American friends.

"You Westerners are very amusing," he chuckled in a heavily accented voice.

"Alexander, you'll have to excuse Rudi," answered a warm, deep voice from the opposite side of the bridge. "He's never lived in an earthquake zone."

The green opaline eyes of Dirk Pitt sparkled with mirth as he helped heckle his deputy. The head of the National Underwater and Marine Agency stood up from a bank of video monitors and stretched his six-foot-three frame, his palms scraping against the deckhead. Though more than two decades of undersea adventures had exacted a toll on his rugged body, he still had a lean and fit form. Just a few more wrinkles around the eyes and a growing tussle of gray at the temples indicated a wavering battle with age.

"An earthquake?" Gunn speculated. The brainy deputy director of NUMA, an Annapolis graduate and former Navy commander, stared out the bridge in wonder.

"I've only been in one or two, but those were felt and not heard."

"Puny ones just rattled the dishes, but larger quakes can sound like a string of locomotives running by,"

Pitt said.

"There is a great deal of tectonic activity under Lake Baikal," Sarghov added. "Earthquakes occur frequently in this region."

"Personally, I can do without them," Gunn said sheepishly, retaining his seat by the monitor bank. "I hope they don't disrupt our data collection of the lake's currents."

The Vereshchagin was engaged in a joint Russian-American scientific survey of Lake Baikal's uncharted current flows. Not one to stay confined in NUMA's Washington headquarters, Pitt was leading a small team from the government research agency in collaboration with local scientists from the Limnological Institute at Irkutsk. The Russians provided the ship and crew, while the Americans provided high-tech sonobuoys and monitoring equipment which would be used to paint a three-dimensional image of the lake and its currents. The great depth of Lake Baikal was known to create unique water-circulation patterns that often behaved unpredictably. Tales of swirling vortexes and fishing boats getting pulled underwater by their nets were common stories among the local lakeside communities.

Starting at the northern tip of the lake, the scientific team had deployed dozens of tiny sensors, packaged in orange colored pods that were ballasted to drift at varying depths. Constantly measuring temperature, pressure, and position, the pods relayed the data instantaneously to a series of large underwater transponders that were positioned in fixed locations. Computers onboard the Vereshchagin processed the data from the transponders, displaying the results in 3-D graphic images. Gunn glanced at a bank of the monitors in front of his seat, then focused on one in particular, which depicted the midsection of the lake. The image resembled a pack of orange marbles floating in a bowl of blue ice cream. Nearly in unison, a vertical string of the orange balls suddenly jumped rapidly toward the top edge of the screen.

"Whoa! Either one of our transponders is going tilt or there's a significant disturbance at the bottom of the lake," he blurted.

Pitt and Sarghov turned and studied the monitor, watching as a flood of orange dots raced toward the surface.

"The current is uplifting, at a dramatic rate," Sarghov said with a raised brow. "I find it difficult to believe the earthquake was severe enough to produce that kind of effect."

"Perhaps not the earthquake itself," Pitt said, "but a resulting side effect. A submarine landslide set off by a minor quake might create that sort of uplift."

A hundred and thirty miles north of the Vereshchagin and two thousand feet beneath the surface, Pitt was exactly right. The rumblings that first echoed across the lake were the shock waves from a strong earthquake, measuring 6.7 on the Richter scale. Though seismologists would later determine that the quake's epicenter was near the lake's northern shore, it created a devastating effect midway down the western flank, near Olkhon Island. A large, dry, barren landmass, Olkhon sat near the center of the lake.

Directly off the island's eastern shoreline, the lake floor dropped like an elevator down a steep slope that ran to the deepest part of the lake.

Seismic studies had revealed dozens of fault lines running beneath the lake floor, including a cut at Olkhon Island. Had an underwater geologist examined the fault line before and after the quake, he would have measured a movement of less than three millimeters. Yet those three millimeters was sufficient enough to create what the scientists call a "fault rupture with vertical displacement," or an underwater landslide.

The unseen effects of the quake sheared off a mountain-sized hunk of alluvial sediments nearly twenty meters thick. The runaway chunk of loose sediments slid down a subterranean ravine like an avalanche, accumulating mass and building momentum as it went. The mountain of rock, silt, and mud fell a half mile, obliterating underwater hills and outcroppings in its path before colliding with the lake bottom at a depth of fifteen hundred meters.

In seconds, a million cubic meters of sediment was dumped on the lake floor in a dirty cloud of silt. The muffled rumble of the massive landslide quickly fell away, but the violent energy produced by the slide was just unleashed. The moving sediment displaced a massive wall of water, driving it first to the bottom ahead of the landslide and then squeezing it up toward the surface. The effect was like a cupped hand pushing under the surface of a bathtub. The force from millions of gallons of displaced water had to be redirected somewhere.

The submarine landslide had fallen in a southerly direction off Olkhon Island and that was the direction that the mounting swell of water began to move. To the north of the slide, the lake would remain relatively undisturbed, but to the south a rolling wave of destructive force was released. At sea, the moving force of water would be labeled a tsunami, but in the confines of a freshwater lake it was called a seiche wave.

An upsurge of water punched the surface in a ten-foot-high rolling wave that drove south along the lake's lower corridor. As the wave pushed into shallower depths, the upswell squeezed higher, increasing the size and speed of the surface wave. To those in its path, it would be a liquid wall of death.

On the bridge of the Vereshchagin, Pitt and Gunn tracked the development of the killer wave with growing alarm. An enlarged three-dimensional map of the lake south of Olkhon Island showed a swirl of orange dots jumping in rapid succession across an expanding line.

"Dial up the surface pods only, Rudi. Let's find out exactly what's going on up top," Pitt requested.