The Alchemist's Code

by Dave Duncan

  “Then who was Eva’s lover? Danese or Giro? Or,” I added with a gulp, “did she have two?” This was Venice, where almost anything is tolerated, but even the canals seldom get as murky as that.

  Violetta laughed. “Oh, my, darling Alfeo! Who are you to judge them? You claim you love me, yet you know how I earn my crusts. Forget Eva and wonder about young Danese. In whose bed did morning find him—Eva’s or Giro’s?” Her lashes fanned my fevered brow. “In my profession, one sees everything conceivable, or otherwise, but I am inclined to guess that Dolfin was the busy one of the three. Remember what Cato said about Julius Caesar?—‘Every woman’s husband and every man’s wife’?”

  And now Dolfin had Grazia also. I could see why Eva had regarded him as an unsuitable match for her daughter. Poor Grazia! When would her gorgeous eyes be opened to the lecher she had married?

  “I must go,” I said, rising. “Tomorrow?”

  “Tonight,” Violetta said. “My evening is free. You can come any time after sunset and stay until dawn—unless you believe that overindulgence will be injurious to your health?”

  “Madonna,” I said, kissing her ear, “I won’t care if it kills me. Until tonight, then!”

  12

  Get him to tell you the one about the sea monster,” I said as I went past.

  The vizio was sitting in the salone telling stories to a pack of Angeli youngsters—Piero, Noemi, Ambra, and Archangelo. No prize for guessing who would be the hero of all of the tales. His eyes measured me for a gibbet.

  The Maestro was at the desk, studying a manuscript folio of Sun of Suns and Moon of Moons by Abu Bakr Ahmad Ibn Wahshiyah, his favorite ninth-century alchemist, known to me as Abu the Confusing. There were no other papers in sight, other than the pile of cryptography books on my side of the desk. Since they had not been disturbed, I concluded that the Maestro was no longer working on the Algol cipher. He might still be working on Algol himself, though. Demons live a long time; Abu might have met him.

  The room was suffocatingly hot. All the windows were open, but not a breath of wind came or went. I could hear the cries of the gondoliers on the canal below as clearly as if I were a passenger.

  “You’re late,” the Maestro said without looking up.

  “I was following up a juicy piece of scandal. It seems that the Sanudo family is vulnerable to blackmail.”

  That got his attention. “Blackmailing a member of the Ten would be a dangerous career. Are you suggesting that Zuanbattista is the traitor, Algol?”

  That was what I was trying not to worry about. I liked Zuanbattista! He had been more than generous to me and unusually kind to his daughter. But it was possible. He had just returned from the Sultan’s court, and a really suspicious mind, like mine, might wonder if his trumpeted success there had been contrived by the Porte to foster his political career here.

  “I hope not,” I said. “He seems to be the injured party. His wife employed Danese, but everyone knows that already. His son probably has uncommon tastes, so he might be vulnerable.”

  My master pouted, took a sheet of paper from under his book, and passed it over. “A fair copy, quickly.” Fair means legible.

  I sat down, opened my inkwell, and then froze. The writing was even worse than his usual scrabbled hand, all badly spaced capital letters, but it was the meaning that stopped me cold:

  …GRAVE SCARS ITADI CORDE ETAST ENUOV EDALL IADAL MAZIA RISOL TAINE STATE MACER COREM ATORI…

  I made that: “…grave scarsità di corde et aste nuove dallia Dalmazia risolta in estate ma cerco rematori…”*

  It went on to discuss powder and shot, caulking, and raw linen for sails.

  I gulped. “Master, is this a report on the Arsenale?”

  He was back in his book again. Still not looking up, he said, “Quite a detailed survey, it seems. The Ten will know whether or not it is accurate and how much damage such knowledge of our navy yard will do in the hands of our foes. Regrettably, that page does not identify the writer. ‘Quickly,’ I said.”

  I opened my pen box and chose a quill. I so often see the old rascal work wonders that I have come to expect them of him, but if he had broken the Algol cipher from the evidence of a single sheet, after the Ten’s renowned experts had failed to crack twenty-four pages in God-alone-knew how many weeks or months, then that miracle would top them all. I passed over the fair copy.

  As he read it, he held out a tiny hand for the original. “Now bring your friend in.”

  His crabby tone suggested that he was pleased with himself. I went to poke my head around the door and whistle for Vasco, then went back to my chair.

  The Maestro laid a ribbon at his page and closed the book. He puckered his thin cheeks in a close-lipped smile. “Ah, Vizio! I have a problem. Sciara dropped a broad hint that the spy known as Algol may have agents within the Ten. He instructed me to report progress to the chiefs, but even they must be to some degree suspect until we know otherwise, right?”

  “I am not privy to such information, Doctor,” Vasco said stuffily.

  “No, you wouldn’t…I have some progress to report already and no further need of those papers you guard so diligently. Which reminds me.” The Maestro opened a drawer and took out a sheet of paper. “This was on the floor in the dining room. It is yours, I think. Now, where was I?”

  Vasco angrily restored the lost sheet to the others in his satchel. He did not look at my smile, which was a masterpiece worthy of extended admiration.

  “When you take the documents back to the palace,” the Maestro continued, “to whom will you deliver them?”

  Smelling traps now, Vasco was wary. “I shall report to Missier Grande, of course. He will probably send me to return the documents to Circospetto, but that will be his decision.”

  Nostradamus nodded. “But Sciara reports to the Grand Chancellor. I must be confident that my information will not disappear in some unfortunate accident. Take a chair. No, on second thought take Alfeo’s, where I can see you more easily. My neck, you know…”

  I never heard him complain of his neck before, but he was certainly up to something. Suppressing outrage at being evicted from my rightful place, I yielded it to Vasco and then stood over him to watch.

  “Alfeo, give the vizio a sheet of paper and a pen. Good. Now, if you please, lustrissimo, write the alphabet along the top. Capitals are easier.”

  “May I help him?” I murmured, but Vasco managed to win through on his own:

  A B C D E F G H I J L M N O P Q R S T U V X Z

  The Maestro had even worse torment in store for him. “Now, write B under A and the rest of the alphabet until you reach Z again, and complete the row with an A.”

  I was already flipping through Giovan Batista Belaso’s La cifra del Sig to find the illustration.

  “You see where you are going?” the Maestro said. “The next row would begin with C, yes? You would end by listing all Caesar alphabets possible with an alphabet of twenty-three letters. If you were to include some of the barbaric runes that northern tribes like the English and Germans use, you would have more.”

  Vasco nodded uncertainly.

  “Alfeo told you how easy it is to break a Caesar cipher. But if you use several Caesars by turn, then the cipher becomes unbreakable! Or so the sagacious Belaso believed and later authorities have agreed. The only thing you need to establish in advance with your correspondent is the order in which you will use the alphabets. No? Well, let us attempt an example. A little farther down the page write the sentence, ‘Sciara, who is furtive.’ In uppercase letters, if you please.”

  Vasco wrote, SCIARA, CHE È CIRCOSPETTO.

  “And then put it in five-letter groups, as Algol does.”

  SCIAR ACHEÈ CIRCO SPETT O

  The Maestro pressed his fingertips together, enjoying his lecture. “Now we shall apply the key, and in this case the word will be VIRTÙ, as that was Algol’s choice. The man has a sense of irony, if not humor. Pray write that under each of the groups.”

 
; SCIAR ACHEÈ CIRCO SPETT O

  VIRTÙ VIRTÙ VIRTÙ VIRTÙ V

  “Excellent. Now leave a line and write out the normal alphabet again. Good. Under it write the Caesars you will use to encipher your plaintext.” He frowned at Vasco’s blank stare—he is accustomed to dealing with my less-circumscribed intelligence. “The first row, you begin with a V…VXZAB…and end with U. The next begins IJLMN…”

  It took a while and Vasco’s rows and columns were not as straight as might be desired, but he got there. The Maestro was beaming.

  “Excellent! We’ll make a scribe out of you yet. Now to begin the encipherment! Under the first letter of the plaintext, S, you see the V of VIRTÙ, yes? So you find S in the normal alphabet, the one that begins with A, and go down to the alphabet that begins with V and what letter do you find?”

  Thoroughly bewildered, Vasco did not find any, so I directed him to P, and he wrote it underneath the S, as instructed. The next letter, C, on the I alphabet, came out as B, and so on. By the time he reached the middle of the second group, he was managing by himself and I was making admiring noises.

  SCIAR ACHEÈ CIRCO SPETT O

  VIRTÙ VIRTÙ VIRTÙ VIRTÙ V

  PBLTN VLAZ…

  “This is absolutely brilliant!” I said. “How in the world did you do it?”

  The Maestro made no effort to appear modest. “The pattern you noticed indicated that a letter’s position within each group was important, so I tried a frequency analysis on the initial letter of each group. It showed too many B’s, so I hypothesized that B stood for either E or A, in which case the Caesar alphabet began with either V or B. Then I tried the second letter of each group, and so on. A rigorous analysis would require more plaintext than just one page, but I found enough clues to work out that the key must be VIRTÙ. It was not so difficult once I recalled the theories of Trithemius, Cardano, Porta, and so on. I’m astonished Sciara and his rabble did not see it. I admit, though,” he added, being hypocritically gracious, “that I have never heard of polyalphabetic substitution ever being used in practice.”

  He had been lucky. Che is not merely a common word in itself; that combination of letters appears in many words in both Tuscan and Veneziano. Whenever it fell in the middle of a five-letter group, it had enciphered as my initials, which had caught my eye. In any other position it was represented by some other triplet, and with another key word it might always be. Then we would not have noticed the repetition. The best ciphers are broken because of human error, Nostradamus had told us, and Algol should never have left the ciphertext in five-letter groupings. That was incredible carelessness.

  Vasco, meanwhile had completed the enciphering and was staring in bewilderment at the result:

  PBLTN VLAZA ZRJVJ L

  He had not even noticed my LAZ in there.

  “So there you are, Vizio,” the Maestro said. “That is how it is enciphered. Now let us try some deciphering. We need to know if the same keyword will work for all four intercepted messages. Page one of one, if you please.”

  With surprisingly little help from me, Vasco managed to reverse the process and start recovering the original plaintext:

  XIAGO ILCON SIGLI ODEID E…

  He stopped. “This is gibberish!”

  The Maestro sighed. “Perhaps the key word is not the same, then.” He was carefully not looking at me, who could read over Vasco’s shoulder. Unlike Vasco, though, I was reading: 11 Agosto. Il Consiglio dei Deci…*

  “Let us try the final dispatch then. Page one of four, please.”

  Again Vasco balked after a few groups, but this time a ray broke through the clouds. “Wait a moment! They begin with dates!”

  XVSET TILPR ESDI…

  15 Settembre. Il presidio…*

  “Why, so they do!” I cried.

  The game was over. Vasco hastily covered his work with his hands.

  “You don’t need to see this!”

  “Of course not,” the Maestro agreed. “You can let Missier Grande into the secret and he can decipher the rest.”

  But I was confident that the Maestro himself would break the news to Circospetto, so he could watch Sciara gnash his fangs in mortification. Vasco looked at him as if suspecting the sort of elaborate hoax that I love to play on him every time I get the chance, but which the Maestro considers beneath his dignity.

  “This nonsense will translate everything?”

  Nostradamus sighed and opened a drawer. “Here is a deciphered version of the page you left in the dining room.”

  It was his own version, and Vasco needed some time to decipher the scrawl and artificial letter groups. As he did, he grew paler and paler.

  “The interesting thing,” the Maestro remarked, and now he was looking at me, although his expression gave away nothing, “was that Circospetto lied to us.”

  “Yes, he did,” I agreed. Today was September 23. If Algol’s fourth dispatch reported news of events on September 15, there had not been time for it to reach Constantinople and the Republic’s spy there to copy it and report back to Venice. Of all the states Algol might be working for, even Rome, the closest, would require almost impossible timing. If the Ten were opening Algol’s mail right here in the city, why did they not know the sender?

  Vasco would never work that out, but before he rose to the bait, the door swung wide and in marched Bruno, carrying a bundle of firewood that would have flattened me. We have taught him to knock on doors, but he does not understand “audibly,” so it does no good. Beaming at us, he delivered his burden to the hearth, then strode out again, leaving the door open.

  “Chilled?” Vasco inquired icily.

  “Important business,” the Maestro said. “I must report to the chiefs. You are welcome to accompany us, Vizio. Go and pack up your things. You can be of no further use here.”

  Almost no other commoner in Venice would have dared speak to Vasco like that, but he took it from the Ten’s consultant. Glowering at me to indicate that our temporary truce was now ended, he stuffed the latest paper in his satchel and departed.

  The Maestro detests having to go out, and I could not recall him ever doing so two days in a row. He must be expecting a handsome reward, in satisfaction, if not in coin. I hurried to my room to don my best. This time I decided to sacrifice good manners on the altar of security, for I knew we were on dangerous business and would be lacking Filiberto’s dubious protection on the way home. I retrieved my rapier and dagger from the top of the wardrobe.

  As Giorgio’s strong oar sped us along the Grand Canal toward the Doges’ Palace, I heard the bells of San Giacomo di Rialto tolling sunset.

  13

  So we returned to the palace and the same chamber we had left not twenty-four hours earlier, the Sala dei Tre Capi. The three chiefs themselves must have been rounded up especially to hear our report, for we were kept waiting only a few minutes and Marino Venier still had crumbs in his beard. The Pope himself could not have asked for greater deference than that. Obviously the government was still extremely worried; La Serenissima was anything but serene.

  The heat of the day had left the room stifling. The lamps were lit, but their glimmer hardly showed against the remains of daylight. As the Maestro shuffled in, leaning on my shoulder, the chiefs were just settling behind their raised table, and the only aide in sight was Raffaino Sciara, the Grim Reaper in blue. Vasco had left us, gone to report to Missier Grande, no doubt. Sciara placed a chair for the Maestro and retreated to the secretaries’ desk. I saw my master seated, then took my place behind him.

  Three old men peered anxiously down at Nostradamus.

  Trevisan was in the center. “Well, Doctor? You wasted no time. What news?”

  I had never seen the Maestro’s pussycat smile better displayed.

  “I have not yet identified your Algol, messere, although I have my suspicions. To confirm or disprove those will take a little longer, but I am satisfied that he exists and I have broken his cipher. I deemed this sufficient cause to interrupt your supper.” />
  Six eyes turned toward Raffaino Sciara. I looked at him also, because I had never seen a skull look humiliated before.

  “You will show Their Excellencies the restored plaintext?” Circospetto demanded acidly.

  “I did not venture to pry into it all,” the Maestro said with false humility. I could tell he was enjoying himself hugely, although the others might not be reading the signals. “I have no need to know the Republic’s secrets. I deciphered one page, just to be sure, and most of it seemed to be street gossip with a few nuggets of intelligence. I can confirm that the key is the same in all the four documents. Alfeo?” He handed me the fair copy I had made for him, and I stepped forward to hand it up to Trevisan. Three heads almost banged together as the chiefs all tried to read it at once.

  “So what is the cipher?” Sciara demanded, quite as furious now as he was supposed to be.

  “A simple polyalphabetic,” the Maestro said mildly.

  “I am impressed, Doctor.” Sciara had to admit that, however sourly, after his minions had failed to crack it. “I have always understood that there was no way of breaking a polyalphabetic cipher.”

  The three chiefs were still muttering together, jabbing fingers at the plaintext.

  “The simple Cardano form used by this Algol person is vulnerable,” the Maestro said, rubbing salt in the wound. “Had he followed the subtler recommendations of the sagacious Monsieur Vigenère and used the plaintext to encode itself, then even I might have failed to break it. As it is, I showed it all to Filiberto Vasco. He will explain the technique to you.” He stretched his lips in a helpful smile.

  I came very close to exploding. The thought of Sciara taking lessons from dear Filiberto was exquisite.

  “We are deeply impressed, Doctor,” Marino Venier growled. “This document appears to be genuine. As you saw, it does include some covert information.” The chiefs were all smiling, though. Their decision to consult Nostradamus had borne fruit and the skeptics within the Ten would have to eat their doubts. “You said you had other evidence for us?”