Dear Mr. Lewis: I hope this missive finds you well. I have taken the liberty of submitting this report to you in the enciphered form upon which we had agreed, with the goal that it should be for your eyes only, and for your sole disposition. I fear that the information enclosed, whether true or not, would excite certain passions, cause men to go into territory where they were ill-prepared to survive, and create problems with the Indians. I understood that you are fully engaged in the formidable task of placing a harness on the Louisiana stallion, but plead your assistance in resolving this matter.

Y’r ob’d’nt s’v’nt, TJ

Lewis deciphered the balance of the encrypted message. Then he went back to the garden diagram. The lines, Xs, circles, and words penned in an ancient language began to make sense of sorts. He was looking at a map—and something about it struck him as familiar. He pawed through dozens of his charts and documents and found what he was looking for.

Taking up pen and paper, he wrote a brief note. He thanked Jefferson for his gardening advice, and said he had located an ideal spot for his crop to flourish, then he told Jefferson that he would discuss gardening when he came to Washington to clear his name. Lewis planned to start down the Mississippi River early in September 1809. He would let Jefferson know when he had arrived in Washington.

It was not to be. Late that fall, Jefferson received a note from a Major Neelly saying that Lewis had died of gunshot wounds on the Natchez Trace wilderness road. He was only thirty-five.

The loss of the talented young man was incomprehensible to Jefferson. It almost seemed as if an ancient curse hovered over the Indian vocabularies. Several weeks later, Major Neelly arrived at Monticello with Lewis’s young slave. While Neelly was cleaning up from his ride, the slave timidly handed Jefferson a packet and whispered a message.

Instructing his staff that he not be disturbed, Jefferson locked himself in his study and studied the packet’s contents. Then he compiled a thorough written analysis of the events leading to Lewis’s death. The dawn’s light was streaming through the windows as he summed up the synopsis in a single underlined word.

Conspiracy.

What if his Indian word lists had been stolen, as the thief had claimed? What if someone knew that Jefferson’s research held the key to an age-old secret? What if the death of Lewis were not a suicide but murder?

Jefferson spent several more days working in his study. When he emerged, brandishing a list of instructions for his staff, he seemed like a man possessed. One night, under cover of darkness, he rode off on his horse, followed in a wagon by his most trusted slaves. Weeks later, they returned, looking tired and disheveled, but there was a glint of triumph in Jefferson’s eye.