Her eyes fluttered shut. “Almost nil. There’s too much lake bottom.” She stirred a packet of artificial sweetener into her coffee. “We’re talking about substantial pieces of the U.S. and Canada. For that matter, there could be something here.” She indicated the floor. “The Fargo area was underwater, too, for a while. Who knows?”

Max looked down at the tiles. “I wonder what the yacht is worth?”

“If it is what we think it is, Max, you couldn’t put a price on it.” She watched a mother trying to balance a squalling child and an armload of packages. “I hope we can actually get some answers to the questions. Truth is, I have a bad feeling that we’re likely to be faced with a mystery no one will ever solve.”

“It would be nice,” he said, “to find something that would help pin down who owned the boat.”

“Remains,” she said. “What we need are remains.” Her manner was so intent that two kids trooping past with balloons turned to stare. “Look. They left the boat. That suggests something unexpected might have happened. A storm. Maybe they were attacked by natives.”

“Or,” suggested Max, “maybe they just never came back for it.”

“It’s a nice boat,” said April. “I’d sure take it with me when I left. I wouldn’t just leave it somewhere. No, I think there’s a good chance something went wrong.” Her voice softened, became very distant. “Oh, Max, I don’t know. I hate to speculate about this thing.” She took a bite of pizza and chewed very deliberately before continuing. “If something did go wrong, there’s a decent chance their means of transportation is still here.”

Max should have been feeling good. The Vickers Museum in South Bend was expected to get a substantial grant, an award that opened serious possibilities for the company. In addition, there had been two good offers for a Catalina flying boat on which Max had an option, and Popular Aviation had notified him they wanted to do an article on Sundown. The company’s condition looked strong enough that he was toying with the possibility of keeping White Lightning.

Nevertheless, he was restless. The ground-search radar was approaching the western limits of Tom Lasker’s farm with no indication of anything untoward. April had hinted at a vehicle. But maybe they were looking in the wrong place. After all, a vehicle wouldn’t have gone into the lake.

Maybe they hadn’t thought this out too well. What was it Lisa Yarborough had said? Think about where they might have stopped off for hotdogs.

The weather stayed cold. He took to watching the Ben at Ten news team out of Grand Forks, which came in on cable. Ben at Ten was covering the Fort Moxie story as a kind of light windup feature each evening. First there was the “devil’s boat” T-shirts. Then there had been footage of angry citizens warning the city council that more people would be frightened away than attracted to Fort Moxie by talk of a devil. They interviewed a man who claimed to have unearthed an intact 1937 Chevrolet in a rock garden in Drayton. They reported on the reactions of out-of-state visitors: The boat was a sign of the last days; it had fallen out of an aircraft; it was a publicity stunt by a boat manufacturer; it was an attempt by the American government to entice Canadian visitors.

Tom complained on the phone that the tent smelled of elephants and that for the first time in his life he was grateful the wind rarely blew out of the south. April was almost frantic that the boat was not locked away securely and not even kept away from the public, but Tom felt a responsibility to his lifelong neighbors to keep it on display. He also sent along a brochure and a T-shirt with a picture of the yacht and the slogan I Had a Devil of a Time in Fort Moxie. The artwork for the brochure wasn’t bad: The boat lay atop its ridge, silhouetted by a full moon with a devilish aspect. The story of the discovery was told in a few terse lines, below a Gothic leader proclaiming that “scientists are baffled.” There were also photos of the Lasker farmhouse and downtown scenes prominently displaying the Prairie Schooner, Clint’s Restaurant, and the Northstar Motel.

Max kept thinking they were looking in the wrong place. On the day that the T-shirt and brochure arrived, he decided to investigate the possibility.

The main branch of the Fargo library is located downtown, at the intersection of First Avenue and Third Street. It’s a square two-story structure, wedged into an area of weary stone-and-brick buildings, softened by trees and occasional shrubbery.

It was midafternoon, just before rush hour, when Max passed the police station and pulled into a parking place in front of the civic center. The temperature had risen, the snow that had been falling since lunchtime had turned to rain, and the asphalt glistened in a cold mist. The streetlights were on, creating a spectral effect, and a heavy sky sagged into the rooftops. He climbed out of the car, pulled his jacket around him, and hurried the half-block to the library.

High-school kids crowded the stacks and tables, and the air was thick with the smell of damp cotton. He went back into the reference section, pulled out all the atlases he could find, and dragged them to a table.

Lake Agassiz had been the largest of the many Pleistocene lakes of North America. It was a sea in every sense of the word, covering at its maximum expanse a surface area of 110,000 square miles. It had formed from the meltwaters of the continental ice sheet near the end of the last ice age. But within a few thousand years those same glaciers, retreating north, had uncovered access to Hudson Bay, and Agassiz had drained.

The ancient lake lived on in Lake of the Woods, the Assiniboine River, Rainy Lake, Red Lake in Minnesota, the Red River of the North, Lake Winnipeg. But in the days of its greatness, the water had filled the valley to a depth of more than three hundred feet.

He checked the dates on Native Americans. They had been here early enough to have seen Agassiz. What else had they seen?

The spruce fibers in the loops of the mooring cables indicated that the boat had been tied up rather than simply anchored. That implied a harbor. Where within a reasonable range of Tom Lasker’s farm had there been a sheltered harbor?

Where, along the shores of Lake Agassiz, would you build a pier?

The size of the coastline was dismaying. It stretched from north-central Saskatchewan to St. Anthony’s Falls in Minneapolis. Probably ten thousand miles of shore. Hopeless. But there was a fair chance that the boat had been moored, that it had broken loose, and that it had been driven onto a reef or sunk by a storm shortly afterward. Not a tight chain of reasoning. But it was possible. If so, then the mooring place lay in the neighborhood. Say, along the western coastline between Fargo and Winnipeg.

He looked a long time at the maps.

What did a good harbor need? Obviously the water had to be at the right level. That made it a problem of altitude. Okay, he could check that out. It would have to provide shelter from current and wind. And enough depth to tie up without grounding during low tide. That meant no shallow slopes. There couldn’t be too many places like that.

He hoped.

Max lifted off, climbed into a clear sky, and turned west, looking for the shoreline. He didn’t find it. The Red River Valley rises in the south, and the escarpment, which is so pronounced near the border, sinks to invisibility. From offshore, the coast would have looked flat. That meant there could have been no deep-water approaches.

He turned north, flying over a snow-covered landscape marked by silos and occasional towns connected by long, quiet two-lane roads. The ancient coast did not appear until he crossed into Cavalier County.

Near Herzog Dam, Route 5 passes through a cut. He went down to four thousand feet for a better look. The snowfields had been abandoned to winter, and nothing moved in all that landscape save a lone pickup, approaching from the east. It was possible the cut disguised an ancient harbor, and he flew overhead several times without coming to a firm conclusion. Unfortunately, if this was it, he doubted there would be much left to look at. He photographed it and flew on.