He owed it to Monk.
He owed it to Meriwether Lewis.
So he said good-bye to Monk at the airport. His friend had been in good spirits. And for good reason. The private jet they’d flown had been stocked with an amazing selection of single-malt scotches. Kat would take Gray’s place at the hospital. And probably just as well. She would keep Monk from hassling his nurses too severely.
The cab slowed to the curb in front of the Archives. Seichan stretched next to him in the backseat.
“Here already,” she mumbled drowsily.
Gray caught the cabdriver staring at her in the rearview mirror as he paid the fare. He couldn’t blame the guy. She’d changed out of her blue coveralls and back into her leather jacket, her black jeans, and a gray T-shirt.
They climbed out of the cab, and both hobbled a bit up the steps. Their bruises, scrapes, and injuries had stiffened up. Seichan leaned on Gray’s shoulder without having to be asked. His hand found her hip without her really needing the added support.
They reached the doors to find Heisman already waiting for them.
“There you both are,” he said by way of greeting. “Come. I have everything in the conference room. You didn’t bring the buffalo hide here by any chance? I would love to see it with my own eyes, rather than that photo you e-mailed.”
“I’m sure that can be arranged,” Gray said.
They entered the same conference room they had been in before to find it all cleaned up again. Only a few books dotted the table. Apparently, deciphering a centuries-old message required merely a couple of spare hours and the same number of books.
As they settled into the room, Gray asked, “How did you solve it so fast?”
“What? Meriwether’s final words? It wasn’t hard. The code that Meriwether used with Jefferson is well known. I’m sure they probably used more involved ones occasionally, but for most correspondence, they used a simple cipher. And considering that Meriwether was writing this as he lay dying, I suspect he went with the cipher he knew best.”
Gray pictured the man, shot twice—once in the gut, once in the head—struggling to leave this last message.
Heisman pushed and sent his chair rolling down the length of the table so he could grab a book. “I can show you. It’s a code based on the Vigenère cipher. It was used in Europe at the time and was considered unbreakable. The key to it is a secret password known only to the parties involved. Jefferson and Lewis always used the word artichokes.”
“Artichokes?”
“That’s right. The code itself involves a twenty-eight-column alphanumeric table to—”
Gray’s cell phone chimed with incoming voice mail. Saved by the bell. “Excuse me for a moment.”
He stood up, stepped toward the door, but pointed back to Seichan. “Dr. Heisman, why don’t you explain all about the cipher to my colleague? I’ll be right back.”
“I’d be happy to.”
Seichan just glared at him and rolled her eyes in exasperation as he left.
Out in the hall, the smile on Gray’s face faded as he read the number of voice mails on his phone. He’d been using the disposable for the past day and forgot to put his battery back into his personal phone until he hit ground again in D.C. Still, apparently it took over forty-five minutes to route and load the calls after he’d powered up.
He stared at the screen.
Maybe this is one of the reasons why it took so long.
He had received twenty-two messages over the past twelve hours, all from the same number. He kicked himself for not calling earlier. He remembered he’d gotten his mother’s first voice mail as they were fleeing Fort Knox. He’d had no time to listen to it then—and it had slipped his mind during all the commotion.
He started from the beginning, already feeling that familiar tension at the base of his spine. He held the phone to his ear.
“Gray, it’s your mother.” She started every phone call that way. Like I don’t know your voice, Mom. “It’s ten-thirty, and I wanted to let you know your father’s having a bad night. You don’t have to come over, but I thought you should know.”
Uh-oh.
Rather than listening to all the messages, he hit redial. Might as well hear how things had gone from the horse’s mouth. The phone rang and rang and then went to voice mail.
That tension in his back squeezed his spine a little tighter. Wanting to know what happened, he listened through the rest of the messages.
“Gray, it’s your mother again. It’s getting bad, so I’m going to call that number for the home-health-care worker you left in case of an emergency.”
Very good, Mom . . .
The next few messages grew increasingly more distraught. The home-health-care worker thought his father was having a bad enough episode to warrant a hospital visit.