Aubrey had greeted them at the top of the gangway and welcomed them aboard the ship. Aubrey was a slightly built man whose flighty energy, sharply pointed nose and nonstop chatter made him resemble an English sparrow. He led them to their cabin. After dropping off their bags, they headed to the mess hall. They settled at a table, and Aubrey brought them cups of tea.

"Damn, it's great to see you," he said. "I'm really pleased you could join our project. How long has it been since we've seen each other, three years?"

"More like five," Gamay said.

"Ouch. Much too long, in any case," he said. "We'll make up for it on this trip. The ship's due to leave in a couple of hours. I often think of you working at NUMA. It must be fascinating," Aubrey said in a voice tinged with envy. "My work on big swirling masses of water pales by comparison with your adventures."

"Not at all, Hank," Gamay said. "Paul and I would kill for the opportunity to do pure science. And from what we've read, your research affects a great many people."

Aubrey brightened. "I suppose you're right. There will be a formal scientific orientation session tomorrow. What do you know about the phenomenon of ocean eddies?"

"Not a lot," Gamay said. "Mostly, that the swirls are a largely unexplored scientific area."

"Absolutely right. That's why this survey is a matter of great importance." He plucked a napkin from its holder and produced a ballpoint pen from his pocket in a gesture the Trouts had seen on a dozen other occasions.

"You'll get to see the satellite images, but this will show you what we're dealing with. We're headed to a site close to the Gulf Stream, about two hundred miles out. This swirl is a hundred miles across, located east of New Jersey, on the edge of the Gulf Stream." He drew an irregular circle on the napkin.

"Looks like a fried egg," Trout said.

Trout liked to kid Aubrey about his penchant for working out scientific problems on restaurant napkins, even suggesting once that he compile them in a textbook.

"Artistic license," Aubrey said. "It gives you an idea of what we're dealing with. Ocean eddies are basically giant, slow-moving whirlpools, sometimes hundreds of miles across. They seem to be cast off by ocean currents. Some rotate clockwise. Others move counterclockwise. They can transport ocean heat or cold, and move nutrients from the bottom of the ocean to the top, affecting weather and creating an explosion of marine life up the food chain, depending."

"I've read somewhere about fishing trawlers working the edges of these things," Trout said.

"Humans aren't the only predators that have discovered the biological implications of eddies." Aubrey sketched out a few more pictures on the napkin and held it up.

"Now it looks like a fried egg being attacked by giant fish," Trout said.

"Actually, as anyone with eyes can see, these are whales. They've been known to feed along the edges of eddies. There are a couple of teams trying to track whales to their feeding grounds."

"Using whales to find whorls," Trout observed.

Aubrey grimaced at the wordplay. "There are better ways to find these puppies than tagging sperm whales. Thermal expansion causes the water inside an eddy to create a bump in the ocean that can be traced by satellite."

"What causes ocean currents to shed these eddies?" Trout said.

"That's one of the things we hope to learn on this expedition. You two are ideally suited for the project. Gamay can apply her biological expertise to the question, and we're hoping you can come up with some of the computer models you're so good at."

"Thanks for inviting us aboard. We'll do our best," Gamay said.

"I know you will. This goes beyond pure science. These big swirls can be real weathermakers. A stalled ocean eddy off the California coast can produce cold temperatures and rain in L.A. Similarly, in the Atlantic an eddy spinning off the Gulf Stream can produce thick fog."

"Not much we can do about the weather," Trout said.

"That's true, but knowing what to expect will allow us to adapt to it. The ocean eddy survey could be vital to the nation's economy. The safety of commercial shipping and the flow of petroleum, coal, steel, cars, grain and computerized cargo depend on accurate weather forecasting."

"Which is why NOAA is so interested in what we're doing," Trout said.

Aubrey nodded. "That reminds me, I've got to talk to the captain about our schedule." He rose from his seat and pumped their hands. "I can't tell you how pleased I am to be working with you guys again. We're having a get-to-know-each-other party tonight." He slid the napkin across the table to Trout. "There will be a quiz on this material in the morning, wise guy."

Luckily for Trout, Aubrey was only joking about the quiz, although the orientation was comprehensive. And by the time the survey ship dropped anchor, both Trouts had become well versed in ocean eddy science. From the vantage point of the ship's deck, the sea in the vicinity of the swirl looked no different from any other part of the ocean, but satellites and computer models had shown it to be moving at approximately three miles per hour.

Trout had done some computer graphics of the ocean bottom in the vicinity of the swirl, and Gamay concentrated on the biological applications. The phytoplankton survey was a vital piece of her research, which was why she was so anxious to get it out of the way.

With the Zodiac rocking in the troughs between waves, they lowered a Neuston net over the side. The net had a rectangular, tubular frame, and the ten-foot cloth net itself was long and tapering, which allowed it to sample large volumes of water. They let out the line so that the net floated partially out of the water. Then they made several tows straight out in a radius from the marker buoys, keeping an eye on the white-hulled NOAA ship to maintain their bearings. The results were good. The net was bringing in solid samples of plankton.

Trout had put the motor at idle and was helping Camay make a last haul when they looked up at the same time at a strange rushing sound. They exchanged puzzled glances and stared off at the ship. Nothing seemed amiss. People were visible, moving about on the deck.

Gamay had noticed a flickering sparkle on the surface of the sea as if the sun were a fluorescent bulb on its last legs. "Look at the sky," Gamay said.

Trout glanced up and his jaw dropped down to his knees. The clouds seemed to be enveloped in a canopy of silver fire that pulsated in brilliant bursts of radiance. He gazed, awestruck, at the heavenly display, and responded with a very unscientific observation.

"Wow!" he said.

The noise they had heard repeated itself, only it was louder this time. It seemed to be coming from the open sea away from the NOAA ship. Trout wiped the drizzle out of his eyes and pointed at the ocean.

"Something's happening at about two o'clock, maybe an eighth of a mile away," he said.

A roughly circular patch of ocean was going dark as if a cloud were casting a shadow.

"What is it?" Gamay said.

"I don't know," Trout said. "But it's getting bigger."

The dark patch was expanding, forming a circle of puckering, wrinkled water. One hundred feet in diameter. Then two hundred feet. And rapidly growing. A glittering band of white appeared at the edge of the dark circle and rapidly developed into a low wall of spume. A low moan rose from the depths as if the sea were crying out in pain.