She sat back in a chair in the library room of the museum and closed her eyes. Shaw thought he had forced her into a dead end by stripping the records. But there were other sources of railroad lore, other archives, private collections or historical societies. Shaw knew she could not afford the time-consuming journeys to check them out. So now she had to think of another avenue to explore. And what Shaw couldn't know, couldn't project in his scheming mind, was that she wasn't trapped at all.

"Okay, Mr. Smart-Ass," she muttered to the silent bookshelves, "here's where you get yours."

She called over the yawning curator, who was still grumbling about inconsiderate FBI agents.

"I'd like to see your old dispatch records and logbooks."

He nodded cordially. "We have cataloged samplings of old dispatch material. Don't have them all, of course. Too voluminous to store. Just tell me what you want and I'll be happy to search it out for you."

Heidi told him, and by lunchtime she had found what she was looking for.

Heidi stepped off the plane at the Albany airport at four o'clock in the afternoon. Giordino was there waiting for her. She brushed off an offer of a wheelchair and insisted on walking on her crutches to the car.

"How are things going?" she asked as Giordino pulled the car into traffic and turned south.

"Doesn't look encouraging. Pitt was poring over aerial photographs when I left the boat. No trace of a branch track showed up anywhere."

"I think I've found something."

"We could damn well use a piece of luck, for a change," Giordino muttered.

"You don't sound enthusiastic."

"My school spirit has been bled out of me."

"Things that bad?"

"Figure it out. The President goes before the Canadian Parliament tomorrow afternoon. We're dead. No way in hell we'll come up with a treaty by then…... even if one exists, which I doubt."

"What does Pitt think?" she asked. "About the train being someplace else besides buried in the river, I mean?"

"He's convinced it never reached the bridge."

"What do you believe?"

Giordino gazed expressionless down the road. Then he smiled. "I believe it's a waste of breath to argue with Pitt."

"Why, because he's stubborn?"

"No," Giordino answered. "Because he's usually right."

For hours Pitt had stared through binocular glasses at the photo blowups, his brain interpreting the detail in three dimension.

The zigzag rail fences separating pastures from bordering woodlands, the automobiles and houses, a red-and-yellow hot-air balloon that made a colorful splash against the green landscape-they were all revealed in amazing clarity. Even an occasional railroad tie could be distinguished on the weed strewn track bed.

Time after time he retraced the almost arrow-straight line between the destroyed bridge and the outskirts of Albany's industrial section, his eyes straining to pick out a minute detail, the tiniest suggestion of an abandoned rail spur.

The secret stayed kept.

He finally gave in and was leaning back in a chair resting his eyes when Heidi and Giordino entered the De Soto's chartroom. Pitt stood tiredly and embraced her. "How's the leg?" he asked.

"On the mend, thank you."

They helped her to a chair. Giordino took her crutches and leaned them against a bulkhead. Then he set her briefcase on the deck beside her. "Al tells me you've drawn a blank," she said.

Pitt nodded. "Looks that way."

"I have some more bad news for you." He said nothing, waiting. "Brian Shaw knows everything," she said simply.

Pitt read the embarrassment in her eyes. "Everything covers a lot of territory."

She shook her head in frustration. "He stole the maps of the old rail line from the museum before I had a chance to study them."

"Do him damned little good unless he'd got a clue to their value."

"I think he's guessed," Heidi said softly.

Pitt sat thoughtful for a moment, rejecting any attempt at cross-examining Heidi. The damage was done. How Shaw came to lay his hands on the key to the enigma no longer mattered. Incredibly, he felt a tinge of jealousy. And he couldn't help wondering what Heidi saw in the older man. "Then he's in the area."

"Probably sneaking around the countryside this minute," added Giordino.

Pitt looked at Heidi. "The maps may be worthless to him. Nothing resembling a rail spur shows on the aerial photos."

She picked up the briefcase, set it in her lap and opened the locks. "But there was a rail spur," she said. "It used to cut off the main line at a place called Mondragon Hook Junction." The atmosphere in the chartroom suddenly galvanized.

Pitt said, "Where is that?"

"I can't pinpoint it exactly without an old map."

Giordino quickly glanced through several topographical maps of the valley. "Nothing here, but these surveys only go back to nineteen sixty-five."

"How did you discover this Mondragon Hook?" asked Pitt.

"Elementary reasoning," Heidi shrugged. "I asked myself where I would hide a locomotive and seven Pullman cars where no one could find them for a lifetime. The only answer was underground. So I began working backward and checked old Albany dispatch records before nineteen fourteen. I hit pay dirt and found eight different freight trains that hauled ore cars loaded with limestone."

"Limestone?"

"Yes, the shipments originated from ajunction called Mondragon Hook and were destined for a cement plant in New Jersey."

"When?"

"In the eighteen nineties."

Giordino looked skeptical. "This Mondragon Hook could have been hundreds of miles from here."

"It had to be below Albany," said Heidi.

"How can you be sure?"

"New York Quebec Northern records don't list ore cars carrying limestone on any freight trains that passed through Albany. But I did run across a mention of them in a dispatch log from the Germantown rail yard where there was a switch of locomotives."

"Germantown," said Pitt. "That's fifteen miles downriver."

"My next step was to search through old geological maps," Heidi continued. She paused and slipped one from her briefcase and flattened it on the table. "The only underground limestone quarry between Albany and Germantown lay here." She made a mark with a pencil. "About nine miles north of the DeauvilleHudson bridge and three-quarters of a mile west."

Pitt put the binocular glasses to his eyes and began scanning the aerial photos. "Here, due east of the quarry site, is a dairy farm. The house and barnyard have erased all remains of the junction."

"Yes, I see it," Heidi said excitedly. "And there's a paved road that runs toward the New York State Thruway."

"Small wonder you lost the trail," Giordino said. "The county laid asphalt over it."

"If you look closely," said Pitt, "you can pick out a section of old rail ballast as it curves from the road for a hundred yards and ends at the foot of a steep hill, or mountain as the natives would label it."

Heidi peered through the binoculars. "Surprising how clear everything becomes when you know what to search for."

"Did you happen to turn up any information on the quarry" Giordino asked her.

"That part was easy," Heidi nodded. "The property and the track right-of-way were owned by the Forbes Excavation Company, which operated the quarry from eighteen eighty-two until nineteen ten, when they encountered flooding. All operations were halted, and the land was sold to neighboring farmers."