We had stepped from the garden into my study, and now sat across from each other at the little tripod table by the window, peering down at the thin pieces of parchment I had extracted from Numerius's shoe. There were five pieces in all, each covered with writing so tiny that I had to squint to make out the letters. At first glance, the text appeared to be pure nonsense, a collection of random letters strung together. I suspected the use of a cipher, with the added complication of mixing Greek and Latin characters.
I tried to explain to Davus how a cipher worked. Thanks to Diana, he had mastered the basic idea that letters could represent sounds and collections of letters could represent words, but his hold on the alphabet was tenuous. As I explained how letters could be shuffled arbitrarily about, then unshuffled, his face registered mounting bewilderment.
"But I thought the whole point of letters was that they didn't change, that they always stood for the same thing."
"Yes. Well…" I tried to think of a metaphor. "Imagine the letters all taking on disguises. Take your name: The D might masquerade as an M, the A as a T, and so on, and altogether you'd have five letters that didn't look like any sort of word at all. But figure a way to see through those disguises, and you can unmask the whole word." I smiled, thinking this was rather clever, but the look on Davus's face was now of confusion verging on panic.
"If only Meto were here," I muttered. The younger of my two adopted sons had turned out to have a genius for letters. His natural gifts had served him well in Caesar's ranks. He had become the general's literary adjutant. To hear Meto tell it, he had done much of the actual writing of Caesar's account of the Gallic Wars, which everyone in Rome had been reading for the last year. No one was more brilliant than Meto at cracking codes, anagrams, and ciphers.
But Meto was not in Rome- not yet, anyway, though expectations of Caesar's imminent arrival continued to mount day by day, causing jubilation in some quarters, terror in others.
"There are rules about solving ciphers," I muttered aloud, trying to remember the simple tricks that Meto had taught me. " 'A cipher is simply a puzzle, solving a puzzle is merely a game, and-"
" 'And all games have rules, which any fool can follow.' "
I looked up and saw my daughter standing in the doorway.
"Diana! I told you to stay in the front of the house. What if little Aulus-"
"Mother is watching him. She'll keep him out of the garden. You know how superstitious she is about dead bodies." Diana clicked her tongue. "That poor fellow looks awful!"
"I wanted to spare you the sight."
"Papa, I've seen dead bodies before."
"But not…"
"Not strangled like that, no. Though I have seen a garrote before. It looks a lot like the one used to murder Titus Trebonius a few years ago, the fellow you proved was strangled by his wife. You kept the garrote as a souvenir, remember? Mother threatened to use it on Davus if he ever displeased me."
"She was joking, I think. Such weapons are as common as daggers these days," I said.
"Davus, are you doing a good job of helping Papa?" Diana moved to her husband's side and laid a slender arm over his brawny shoulders, then touched her lips to his forehead. Davus grinned. A strand of Diana's long black hair fell across his face, tickling his nose.
I cleared my throat. "The problem appears to be a cipher. Davus and I have practically solved it already. Run along, Diana, back to your mother."
"Isis and Osiris, Papa! How can you possibly read such fine writing?" She squinted at the parchment.
"Contrary to prevailing opinion in this household, I am neither deaf nor blind," I said. "And it is unseemly for girls to speak impiously in front of their fathers, even if the deities invoked are Egyptian." A passion for all things Egyptian was Diana's latest rage. She called it a homage to her mother's origins. I called it an affectation.
"I'm not a girl, Papa. I'm twenty years old, married, and a mother."
"Yes, I know." I looked sidelong at Davus, who was completely absorbed in blowing wisps of his wife's shimmering black hair away from his nose.
"If solving a cipher is the problem, Papa, then let me help you. Davus can go stand watch in the garden, to make sure no one else comes over the rooftop."
Davus brightened at this suggestion. I nodded. He strode off at once. "You, too, Diana," I said. "Off with you!" Instead, she took Davus's place in the chair across from me. I sighed.
"It needs to be done quickly," I said. "The dead fellow out there is a relative of Pompey's. For all I know, Pompey may have already sent someone looking for him."
"Where did these pieces of parchment come from?"
"They were hidden in a secret compartment in his shoe."
Diana raised an eyebrow. "This fellow was one of Pompey's spies?"
I hesitated. "Perhaps."
"Why did he come here? Why did he want to see you, Papa?"
I shrugged. "We hardly spoke before I left him alone for a moment."
"And then?"
"Davus came into the garden, found his body, and raised the alarm."
Diana eagerly reached for a sheet of parchment. "If we look for vowels, and common consonant combinations-"
"And common words, and case endings."
"Right."
"Or likely words," I added.
"Likely?"
"Words likely to occur in a document carried by Pompey's spy. Such as… such as 'Pompey,' for example. Or more likely, 'Magnus'- Great One."
Diana nodded. "Or… 'Gordianus,' perhaps?" She looked at me askance.
"Perhaps," I said.
Diana fetched two styluses and two wax tablets for scribbling notes. We studied our separate pieces of parchment in silence. Out in the garden, Davus paced back and forth in the sunlight, whistling tunelessly and scanning the roof. He pulled Numerius's dagger from its scabbard and cleaned his fingernails. From the front of the house came more screams from Aulus, and then the sound of Bethesda crooning an Egyptian lullaby.
"I think…"
"Yes, Diana?"
"I think I may have found 'Magnus.' I see the same sequence of letters three times on this piece. Look, there it is on your piece, too."
"Where?"
"There: ?V?C?Q
"So it is. By Hercules, these letters are small! If you're right, that gives us ? for M, V for A…"
"? for G…"
We scribbled on our wax tablets. Diana scanned her piece of parchment, put it down and scanned two others. "Papa, may I see your piece?"
I handed it to her. Her eyes moved down the page, then stopped. She sucked in a breath.
"What is it, daughter?"
"Look, there!" She pointed to a group of letters. They began with ? and ended with C?Q- or, according to our cipher, began with a G and ended with nus- and had five letters between.
" 'Gordianus,' " she whispered.
My heart pounded in my chest. "Maybe. Forget the other pieces for now. Let's work together on this one."
We concentrated on the section of text immediately following my name. It was Diana who spotted the large numbers strewn throughout; rather than quantities, they appeared to be years, following Varro's fashionable new system of dating everything from the founding of Rome. The cipher letters for D and I (presumed already from GORDIANUS) turned out to stand as well for the numerals D (five hundred) and I (one). Deciphering the years also gave us the letters for C, L, X, and V.
Using our growing list of deciphered letters, we quickly spotted familiar names embedded in the text. There was METO, and CAESAR… ECO (my other son)… CICERO… even BETHESDA and DIANA, who seemed more amused than alarmed at seeing her name in a dead man's document. As we made further progress, the most devious feature of the text became obvious: not only did the cipher mix Greek and Latin letters, but the text alternated between phrases in both languages, with a patchwork of truncated and irregular grammar. My Greek had grown rusty in recent years. Fortunately, Diana's Egyptomania had included brushing up on the language of the Ptolemies.