Eric Flint: Grantville Gazette.Volume 22

"While I'm at it, Your Grace, I would like to send Grantville some additional hair samples for testing. My hair, Marina's, Cosimo's and your own, perhaps. We'll make sure that no one is putting arsenic in your soup, that way, and the rest of us will act as controls."

"See to it. Tomorrow morning I will have a courier take it to Venice. It can be there in two days, and then catch the next flight to Grantville. And your colleagues can radio the results to Venice to save time. All I ask is that the communications not reveal anyone's names."

"I wouldn't want them to. I will number the hair samples, so the testers won't be influenced in any way."

"These results… are very strange."

"How so?" asked Marina.

"Okay. Look at the report. Sample 1 is your hair, that was the main control."

"Why not your hair?"

"Well, since I've been in Italy for a few months, and I have made few enemies, I couldn't be sure that no one was poisoning me."

"Oh."

"Anyway, your levels are low. About one part per million. So are mine, and Cosimo's, and even the grand duke's, for that matter. All under five parts per million. But now look at Sample 5."

Marina stared at the graph. "That's weird. They're up and down, on a regular basis. But… the peaks get higher and higher. And then the last peak is way up. So what does it mean?"

"First of all, these peaks are way above what a seventeenth-century Italian would naturally be exposed to. So Pietro was being poisoned all right."

"Which I thought we knew already, from the Marsh test on his tummy-wummy."

"Yes, Marina, but it was nice to get that confirmed by a more sensitive test.

"Second, Pietro suffered both chronic and acute arsenic poisoning. Which means that either our poisoner kept notching up the dose, and finally got impatient for some reason and hit him with the chemical equivalent of a two by four…"

Marina finished his thought. "Or we have two poisoners, working independently."

"Cosimo, I need to construct a plan of the house," Lewis said.

"What good will that do?"

"When a general is planning a battle, he consults a map of the terrain, does he not? When a detective investigates a crime in a house, he needs a house plan."

Cosimo shrugged. "All right, that makes sense. Perhaps I can borrow an assistant from one of the grand duke's architects; he'll do a better job than we could."

"Fine, Cosimo, but I need exact dimensions, not just a general layout. I want the length and height of every wall measured, and every corner checked to make sure that it's a right angle. I want to know the apparent thickness of every wall, beginning to end."

"You're looking for secret rooms?"

"Yes, like the priest's holes the Catholics in England have. Or even just a little hiding place."

"There, Cosimo, just as I thought. The dimensions of the study aren't right. This wall should be a foot further away from the windows, to match the next room over."

"So what does that mean?"

"A false wall, and something behind it." Lewis put his ear against the wall, and tapped it.

He then did the same for one of the other walls.

"I believe the far wall is hollow. You try it."

Cosimo did just that. "I guess we need to go get some axes," he said cheerfully. The thought of a little authorized mayhem, even directed against the inanimate, was apparently pleasing to his martial spirit.

Lewis rubbed his chin. "Let's not be hasty. If the secret compartment, or whatever, was accessed frequently, his lordship certainly wasn't bashing in the wall each time. Start feeling around for a hidden panel."

They found it eventually, just below the ceiling. It had been superbly designed; it was no wonder they hadn't found it the first time they searched the house. The compartment it concealed wasn't that big, but it was big enough to hold some oddly marked vials, and a journal. Lewis handed them down to Cosimo, then stepped off the chair.

One of the vials contained a white powder. Lewis pointed to it, and Cosimo handed it over. Lewis pulled out the cork, and waved his hand over the top, wafting the released air toward him. "I'll have to test it, but I think it's arsenic. I wonder what the book says."

Cosimo had already started leafing through it. "Makes no sense to me."

"Here, let me. After reading the Latin mumbo-jumbo the alchemists write, I am pretty good at understanding esoterica. Not to mention reading really bad handwriting."

Cosimo handed the book over, with a slight smile.

"Why are you smirking, Captain? Oh." The text was clearly encyrypted. "I guess I'll save that for later."

Lewis had taken the first steps to solving the secret text. First, he tabulated all the symbols used on the first few pages. There were 26 different ones, which implied that each stood for a letter of the Renaissance Latin alphabet. It was just what Sherlock Holmes had done in "The Adventure of the Dancing Men."

However, Lewis couldn't be sure whether the cipher was in Latin or Italian, and in any event, Lewis didn't have frequency tables for either language. That problem was easy enough to solve; he gave Cosimo and Marina a few texts in each language, and had them compile tables for him.

In the meantime, he made a frequency table for the cipher. He was relieved to discover that it seemed to have the characteristic look, in terms of variation in frequency among the letters, of a monoalphabetic substitution cipher. That is, one in which each letter of the plaintext was replaced with a single cipher letter, and always that letter. Lewis had read that polyalphabetics had been invented in the fifteenth century, and wasn't at all sure that his deciphering skills were up to tackling one.

"Here you go," said Marina. "I hope this is based on enough data. I'll go blind if I look at any more Latin gobbledegook today."

Lewis looked it over. From most to least, it ran E A I T U… English would be E T A O N… Fortunately, with so much cipher text to work from, it would be easier to solve than even a newspaper cryptogram. Assuming that Lewis hadn't made any mistakes in converting the symbols into letters, and that Pietro, or whoever, hadn't thrown in too many nulls, abbreviations, code names or mistakes.

Marina looked over her shoulder. "I can tell you what it says. 'Dear Diary'…"

"You're right, Maria, it is a diary. Although each entry begins with a date. So I will decipher the first few entries, and then switch to the last ones."

"Fine. I am going out."

"Okay, you know the drill. Summon the coach, have them wait for you, don't go off with any strange men. Actually, with any men."

"Yeah, yeah." She gave him a vague wave and went looking for a footman.

Lewis went back to work. He was still working when she returned, late in the evening. But he was able to tell her something important. The text wasn't a diary, exactly. It was a journal. An experimental journal.

The next morning, when Cosimo arrived at the door, Lewis was waiting for him. "Cosimo, we need to visit a few apothecaries," said Lewis. "Oh, tell Carlo and Rocco I would like them to dress as servants, not soldiers. We are going to collect information, not to make arrests. I'll explain along the way."

"I understand you have solved the mystery," the grand duke declared.

"I think so, Your Grace. Pietro poisoned himself."

"Suicide? That is a serious charge-"

Lewis held up his hand. "Forgive the interruption, but while the poisoning was deliberate, the result was accidental."

"Explain."

"You will recall the testimony of the Lady Silvia that Pietro thought that someone was poisoning him. He questioned and fired a few servants, but of course he then had to hire new ones, who he soon suspected in turn. In desperation, he began his experiments."