“I see what you’re driving at,” Angela said. “But this jar is a lot smaller than the stone would have been. What about the scale?”
“I’ve been thinking about that, and I don’t think it matters. I know a bit about mapping and, as long as you know the scale, you can interpret a map of any physical size. That diagram”—he pointed at the skyphos—“isn’t a conventional map because it hasn’t got a scale, at least as far as I can see, and it doesn’t show any features like a coast, rivers or towns. I’ve been trying to put myself in the position of the man who prepared it, trying to work out what he could have done to create a map that would endure, if necessary for centuries.
“If the burial place was outside Rome, he wouldn’t have been able to use buildings as reference points, because the only structures he’d see out in the country wouldn’t have been permanent. I mean, if he’d buried something in Rome itself, he might have guessed that places like the Circus Maximus would survive and used them to identify the location of the burial place. But in the country, even a large villa might be abandoned or destroyed within a generation or two. So the only realistic option he would have had would be to use very specific geographical features.
“I think Marcellus—or whoever made this—picked permanent objects, things that, no matter what happened in Italy, would always be visible and identifiable. I don’t think this diagram needs a scale because it probably refers to a group of hills near Rome. I think the lines show the distances between them and their respective heights.”
For a few seconds Angela looked at the diagram on the side of the skyphos, then down at the drawing Bronson had made, her fingers tracing the letters and numbers he’d copied from the vessel. Then she grabbed a book about the Roman Empire, flicked through it until she reached the index and turned to a specific page. It contained a table with letters and figures, but Bronson couldn’t read it upside-down.
“That might make sense,” she said, her eyes flicking between Bronson’s copy of the diagram and the table in the book. “If you’re right and the lines represent distances, then ‘P’ would translate as passus, the pace step of a Roman legionary and equal to 1.62 yards. ‘MP’ would mean mille passus, one thousand passus. That’s the Roman mile of 1,618 yards. The ‘P’ markings beside the dots would probably represent the heights of the hills, measured in pes, plural pedes, the Roman foot of 11.6 inches, and
‘A’ the actus, 120 pedes or about 116 feet.”
“But would the Romans have been able to produce figures that accurate?” Bronson asked.
Angela nodded confidently. “Absolutely. The Romans had a number of surveying tools, including one called a groma. That had been in use for centuries before Nero’s reign and would have allowed for quite sophisticated measuring. And you should also remember how many large Roman buildings are still standing today. They wouldn’t have survived if their builders hadn’t had quite advanced surveying ability.”
Angela leaned over the keyboard of the laptop, typed the word “groma” into the search engine and pressed the “enter” key. When the results appeared, she picked one site and clicked on that.
“There you are,” she said, pointing at the screen. “That’s a groma.”
Bronson looked at the diagram of the instrument for a few moments. It comprised two horizontal arms crossed at right angles and resting on a bracket that was itself attached to a vertical staff. Each of the four arms had a cord at the end that formed a plumb bob.
“And they also used a thing called a gnomon to locate north—very roughly—and they could measure distance and height using a diopter. ”
“So all we have to do now is work out which hills Marcellus used as his reference points.”
“That sounds easy, but only if you say it quickly,” Angela commented wryly. “How the hell are you going to manage that? There must be hundreds of hill formations outside Rome.”
“I have a secret weapon,” Bronson said, with a smile. “It’s called Google Earth, and I can use it to check the elevation of any point on the surface of the planet. There are six reference points on that diagram, so all I have to do is convert the figures from it into modern units of measurement, and then find six hills that match those criteria.
“Then we find the liars.”
II
On the way back from Ponticelli to Rome, Gregori Mandino telephoned Pierro and ordered him to wait at a restaurant on the Via delle Botteghe Oscure. By the very nature of the business he was in, Mandino had no office and tended to hold most of his meetings in cafés and restaurants. He also told Pierro to find detailed maps of the city and the surrounding area, and of the structures built in ancient Rome, and bring those with him, along with a laptop computer.
They met in a small private dining room at the back of the restaurant.
“So you found the Exomologesis?” Pierro asked, once Mandino and Rogan had sat down and ordered drinks.
“Yes,” Mandino replied, “and I really thought that would be the end of the matter.
But when Vertutti unrolled the scroll completely, there was a postscript to it that we hadn’t expected.”
“A postscript?”
“A short note in Latin accompanied by the imperial seal of Nero Claudius Caesar Drusus. It gave Vertutti quite a scare, because it implied that the scroll was only a part of what Marcellus had hidden on Nero’s instructions, and wasn’t even the most important part at that.”
“So what else did he bury?”
Mandino told him what Vertutti had translated from the Latin.
“Are you serious?” Pierro asked, a slight but perceptible tremor in his voice. “I can’t believe it. Both of them?”
“That’s what the Latin text claimed.”
The academic looked distinctly pale despite the warm lighting of the room. “But I don’t—I mean—oh, God. You really believe that?”
Mandino shrugged. “My views are irrelevant. And I frankly don’t care whether what’s written on the scroll is true or not.”
“Could those relics really have lasted two thousand years?”
“Vertutti isn’t prepared to take the chance. The point, Pierro, is that we’re still under contract to resolve this, so I’m expecting you to decipher what’s on the stone.”
“Where is it now?”
“We’ve left it in the car. Rogan has taken pictures of the inscription, and you can work from those.”
Rogan handed over the data card from the digital camera.
Pierro slipped it into a document pocket on his computer bag. “I’d like to see the stone for myself.”
Mandino nodded. “The car’s just around the corner. We’ll go and take a look at it in a few minutes.”
“And what exactly is the inscription? A map? Directions?”
“We’re not sure. It’s definitely the lower section of the stone with the Latin inscription—we put the two pieces together and they match—but it seems to be just three straight lines, six dots and some letters and numbers. It’s more like a diagram than a map, but it must indicate where the relics are hidden, otherwise there would have been no point in carving it in the first place, and no reason for anyone to hide the stone.”
“Lines?” Pierro murmured. “You mentioned letters and numbers. Can you remember what letters? Perhaps ‘P’ and ‘MP’?”
“Yes, and I think ‘A’ as well. Why? Do you know what they mean?”