“Please,” she said, indicating a chair. “But how did you get in here? The museum’s closed.”
“Someone must have left a door unlocked. Now, if you don’t mind, could we chat about the bone?”
“I was just writing up the results.”
The man waved his hand. “I’d much rather hear it from you directly. I’m in something of a hurry.”
“All right.” She paused, recovering from her surprise, collecting her thoughts, determining where to start. “First of all, the size and robustness of the bone suggests a male. Someone with big, strong hands. The muscle attachments were so pronounced that I can say with confidence this person performed daily work, hard manual work, involving grasping and holding.”
“Interesting.”
“The distal end of the bone was severely abraded at the time of death. It seems the man literally scratched or clawed his finger to the bone. I’ve never seen anything like it, and I’m at a loss to explain.”
The pale man sat in silence for a moment. Then he spoke. “The gentleman in question was walled up alive.”
Ganesh leaned forward. “Really?”
A nod.
“So this is a murder investigation?”
“Of an antique sort.”
“I see.” She cleared her throat. “The bone was well preserved and had plenty of collagen. I did a radiocarbon date on the sample. It’s fairly recent, relatively speaking. Because of that the age was a little hard to measure, but it appears to date back one hundred forty years, plus or minus twenty.”
“And there’s no way to narrow the margin of error, I understand.”
“That’s correct. Radiocarbon dating works best on artifacts between five hundred and fifty thousand years old. The error bars get longer at both ends.”
“Did you use beta counting or mass spectrometry?”
Ganesh was amused by this. Here was a man trying to show off his knowledge, but he knew just enough to ask a dumb question. “With such a recent date, only accelerator mass spectrometry would give a usable result.”
“I see.”
And now she wondered if, rather than being dumb, maybe he had been testing her. What a strange and compelling man this was. “With the abundance of collagen and the lack of contamination, I did manage to get some really good DNA results. The individual is definitely male, with seventy-five percent African ancestry, the other twenty-five percent western European.”
“Curious.”
“This is a typical mix for African Americans, almost all of whom have a proportion of European ancestry. He would have had a dark but probably not black skin color.”
“And his age?”
“A histological examination indicated an age of around forty. It also showed he was in excellent health, aside from several short but severe bouts of an illness when he was young. Thin sections I studied indicate the illness might well have been scurvy—a severe vitamin C deficiency.”
“The fellow was a sailor, then?”
“The evidence points that way. The same isotope analysis showed a diet high in fish, shellfish, wheat, and barley.”
“How can you tell that?”
“The food you eat and the water you drink get broken down and the carbon, oxygen, and nitrogen become incorporated into your bones. Those three elements have various stable isotope ratios, which differ from food to food—and from water sources. Based on the ratios of those isotopes, we can tell what a person was eating and drinking during, say, the last twenty years of his or her life.”
“Drinking?”
“Yes. As you go higher in latitude, the ratio of oxygen isotopes in freshwater changes.”
“Interesting. And at what latitude did this fellow’s drinking water come from?”
“From around 40 to 55 degrees. In North America, that corresponds to an area roughly from New Jersey to Newfoundland and points west. The test is not very accurate.”
“And his diet?”
“The wheat came from eating bread, and the barley most likely came from beer. Add the fish and shellfish and you get a classic nineteenth-century coastal diet. I tested the bone for antibodies. They came back positive for malaria.”
“Malaria again implies a sailor, no?”
“Absolutely. And he was also positive for TB.”
“You mean he had tuberculosis?”
“No. He was far too healthy. Virtually everyone living in seaport cities in the nineteenth century would have tested positive for TB, however. Everyone was exposed.”
“I see. Anything else?”
“Putting it all together, I’d say what you have here is a large, strong, healthy, forty-year-old African American male, a sailor by trade who worked with his hands, perhaps a helmsman or foretopman, who probably came from a fairly comfortable socioeconomic class, given there were no signs of malnutrition other than the scurvy. He was born around 1840 and died around 1880. When not at sea he lived in a seaport town or city. He sailed at least part of the time in the tropics.”
The FBI agent nodded slowly. “Remarkable, Dr. Ganesh. Truly remarkable.”