The Cartographers(51)

“What’s so special about this Sanborn map, then?” she asked.

“It’s rare,” Eve allowed. “A seventh edition.”

“Why is the seventh edition so rare?” she asked.

“Your father wouldn’t want—”

“I know, I know,” Nell replied, frustrated. It had been the same with Ramona. She could get them talking a little about the past, but the more she tried to get them to open up in detail about the present, about anything that could somehow be related to the secret surrounding the gas station map, they’d clam up. And Francis had been even worse.

An idea occurred to her suddenly, as she fretted.

“Tell me, and I’ll drop it,” Nell offered. That was what all three of them wanted her to do, wasn’t it? And the tactic had worked on Ramona, just enough to get her to give Nell the Sanborn.

Eve studied her, sizing up the truth of that claim. “Prove it,” she said at last. “Give the Sanborn map back to me.”

Nell hesitated. She didn’t want to give up her only clue. But if Eve would tell her why her father had wanted it so badly, maybe she wouldn’t need it anymore.

And she still had the gas station map. The one that really mattered.

At last, Nell gently eased the map a little closer to Eve, so it was in front of her instead of between them both.

“Why is the seventh edition so rare?” she repeated softly.

Eve took a breath. “Because it was discovered to be inaccurate,” she finally replied. “Remember, these maps were used by insurance underwriters to determine the risk of damage or complete destruction of a given building due to accidental fire or flood, in order to charge the landlords the right premium. Precision was of the utmost importance. Once the inaccuracy was discovered here, the eighth edition was rushed out, and most of the seventh editions were probably trashed, to prevent confusion.”

“Inaccuracy? Like the measurements were off?” Nell tried.

“No,” Eve said. “Like a phantom settlement.”

“A phantom settlement?” Nell repeated.

“You must have a specialization in ancient maps,” Eve said, smiling. “Just like your mother.”

“How did you guess?” Nell asked.

“Because phantom settlements are a very modern cartographic issue,” she replied. “They do occasionally occur in ancient maps, but they’ve mostly been labeled as errors in those cases, although some of that is up for debate.”

At the far end of the booth, someone had come to peruse the gallery of Sanborn maps hanging beneath the lights, startling Nell. Eve waited until they’d moved on before she continued.

“In any case, this concept wouldn’t have come up in your ancient-era research because in those times, most people couldn’t read, let alone copy something as sophisticated as a map.”

Nell nodded. It was the curse of a doctoral degree—one’s specialized knowledge was incredibly deep, but narrow. She and Felix had delighted endlessly in teaching each other things from their respective concentrations, amazed at how different every era or every country’s maps could be from each other. “How modern?” she asked.

“Just within the last hundred or two hundred years,” Eve replied. She looked at the Sanborn map on the table before them again. “Once the general public had largely become educated, and mapmaking was no longer an arcane art, but a rather commonplace business. Too commonplace, in fact. These days, a cartographer can work for months and months to survey an area and produce a map, only to have all that hard-earned data simply stolen by a competitor.”

“There are laws protecting intellectual property against that kind of fraud,” Nell said.

“Of course. But this is the border between art and science. Two painters can sit before their easels facing the same subject, and their creations will turn out completely distinct. A map is not a painting, though. A map must depict only what is there—the truth—precisely and without interpretation. Thus, if two maps are both perfectly accurate, how would you actually prove that someone had stolen your work to make their own?”

Nell started to speak, and then paused. “I don’t know,” she finally admitted. The threat had simply never been an issue for any of the cartographers in her era. “Kind of a paradox.”

“Very,” Eve agreed. “But someone finally figured out a loophole. No one knows who first came up with the solution to protect the original creators, but it was genius. Hide a lie inside the truth.”

“A trap,” Nell said.

“Exactly,” Eve replied. “A phantom settlement.”

“If whatever you planted ever appeared on someone else’s map, you’d know they had stolen from you, instead of done the work themselves,” she mused. “It is genius.”

“The trick is hiding it well enough. An incorrect altitude on a minor mountain, a misspelling of a small body of water, a slight bend in an out-of-the-way river that’s actually straight. In small-scale maps, which depict buildings and floor plans, we tend to refer to these phantom settlements, these secrets, as just that: trap rooms.”

Nell couldn’t help smiling despite the somber reason for their meeting. Ancient maps had always held more prestige and wonder for her, but she had to admit that there was still some magic in modern maps, too. How many times had she opened a tourist guide to some city or another while traveling, and glanced right over some cartographer’s little secret just like this, without ever knowing?