The professor was in class, so Harris left a message. With Angela’s permission, he copied the material. He’d been so intent on the written text that he had paid little attention to the drawing.

Angela saw him studying the lines and Xs. “That’s the other part of the mystery. I thought it was a garden layout at first.” She told him what she had found on the ancient-languages website.

“Fascinating, but let’s concentrate on the main text message for now.”

Harris made copies of the papers. Angela tucked the original documents back into her briefcase. Harris walked her to the door and said he would let her know what he learned. Two hours later, he got a call from his professor. Harris started to tell him about the cipher problem. He only got as far as the name Jefferson when the professor told him to come over immediately.

Professor Pieter DeVries was waiting for Harris at the other side of the security check-in. The professor practically dragged Harris to his office in his haste to look at the file.

The professor epitomized the brilliant but absentminded mathematician that he was. He tended toward tweed suits, even in the warmer months, and had the habit of tugging at his snowy Vandyke beard when he was engaged in thought, which was most of the time.

He studied the artichoke file. “You say a young lady from the Philosophical Society brought this to you?”

“That’s right. She works in their research library.”

“I probably wouldn’t have given it a second look if not for the grille,” which Angela had let Harris hold on to. He picked up the perforated cardboard, stared at it with disdain, and then set it aside. “I’m surprised Jefferson would have used something as crude as this.”

“I’m still not convinced this stuff conceals a message,” Harris said.

“There’s one way to find out,” the professor replied.

He scanned the columns of letters into a computer and tapped the keyboard for a few minutes. Letters arranged and rearranged themselves on the screen until a word popped up.

EAGLE

Harris squinted at the screen and laughed. “We should have known. Eagle was Jefferson’s favorite horse.”

The professor smiled. “Babbage would have sold his soul for a computer with tenth the capacity of this machine.” He typed the key word onto the screen and then instructed the computer to use it to decipher the message he had scanned earlier.

The letter Jefferson had written to Lewis in 1809 came up in plain text.

Harris leaned over the professor’s shoulder.

“I can’t believe what I’m reading,” he said. “This is crazy.” Harris dug out the paper with the odd drawings on it. “Angela thinks these words are Phoenician.”

“That concurs with what Jefferson’s source at Oxford says in his letter.”

Harris felt a great weariness. “I’ve got the feeling that we may have stumbled onto something big.”