A Conspiracy in Belgravia

by Sherry Thomas

  Charlotte absconded with half a dozen of the madeleines. She sat down at her desk and examined the plaintext message again, stuffing the first still-hot madeleine into her mouth. As the little cake disappeared into her stomach, her brain suddenly . . . sprouted.

  Of course. Now she saw the error of her ways. She had been so consumed by the Vigenère cipher that she—horrors—hadn’t been eating properly. A quick glance at the mirror told her that she was down to only one point three chins. No wonder her brain was so slow and unwieldy, like a steam engine on the last shovel of coal.

  Two more madeleines and she felt like a new woman.

  The O’s. What if they weren’t letters? What if they were instead numbers?

  Zeroes.

  And if they were zeroes, that would make the I’s or the L’s ones.

  According to her notes, I’s were overrepresented, acceptable given that the other vowels must compensate for the shortage of O’s. But L’s, like O’s, were underrepresented. And when she thought about the distance measured in thousands of yards . . . What if the cipher writer had been trying to avoid more reasonable units such as miles or furlongs, which would have put an L where it did not belong?

  She made a fresh copy of the plaintext and underlined all the L’s and the O’s.

  Much that remained in the ancient valley had been ransacked by raiders in later centuries. The ruins were a sad sight, decrepitude sans grandeur, an insipid past that inspired little beyond a gloomy sigh. We were glad as we departed, leaving behind the mounds of rubble and that general air of mournfulness. Onward! Lucky for us, our next destination, a thousand yards eastward as the hawk flies, was as magnificent as this one was inferior. The granite edifice must have been a palace in its heyday and the treasures within must have been astonishing. My friend, pray excuse my brevity. Let me dig instead and write again when I have unearthed artefacts and other archaic gems.

  The L’s and O’s, once converted into ones and zeroes, respectively, made a string of numbers thirty-one digits long: 1111101001100110010100001001010

  She translated it into Morse code, dashes for ones and dots for zeroes. But no matter how she parsed the resultant sequence of dots and dashes, they refused to make any sense. And if they, too, were a code, then she didn’t have a long enough sequence for decoding.

  Deciphering, a science and art only for those with no fear of ending up in any number of blind alleys.

  She nibbled on the next madeleine, hoping this wouldn’t turn out to be a six-madeleine problem, because she had hopes of stowing away the last two for a late-night snack. But what else was she to do with a passel of ones and zeroes?

  She stopped midchew. Ones and zeroes, when used in a binary system, could convey other numbers. The calculation might be a bit tricky. To convert a thirty-one-digit binary number, she would need to calculate powers of two up to the thirtieth, which promised to be a sizable number. Nevertheless, it would be much, much easier than cracking a Vigenère code—orders of magnitude easier.

  But what purpose would the resultant number serve?

  She could take out any passage from any book or newspaper, underline the L’s and the O’s, turn them into ones and zeroes, and arrive at a binary number.

  Her gaze went around the room and landed on an item she had recently bought, a well-made object at once beautiful and very, very useful.

  Hmm. She might just know what to do if she had two numbers.

  Eight

  As Lord Ingram Ashburton’s hansom cab approached Mrs. Watson’s house, his attention was ensnared by the middle-aged nanny pushing a perambulator.

  A nanny out and about in these parts was a perfectly common sight. Mrs. Watson’s house faced a large, verdant park. At any point during the day there could be nurses, nannies, and governesses taking their charges for some fresh air. The thing was, he was almost entirely sure that this particular nanny had been selling cigarettes and boutonnieres two days ago, when he last passed before the house—but did not, in the end, choose to ring the doorbell.

  He didn’t ring this time either.

  Before his vehicle had come to a full stop, Charlotte Holmes, clad in a burgundy-and-cream-striped dress, stepped out of the front door, a cream parasol in one gloved hand, a burgundy handbag in the other, the whole ensemble capped off by a toque festooned with jaunty burgundy feathers.

  On another woman, this would have been dramatic. On Holmes, it passed for austere—he was far more accustomed to seeing her in sartorial concoctions that featured endless yards of laces, fringes, and ruffles, a mobile ribbon stand of a woman.

  “May I offer you the use of a conveyance, miss?” he said.

  She couldn’t possibly have been expecting him, but judging by her perfectly composed expression, one would have had reason to conclude that he stopped before Mrs. Watson’s house at this hour every day to present the use of a for-hire carriage. “Thank you, sir. You may indeed.”

  To the cabbie she said, “Portman Square, please.”

  Lord Ingram raised a brow. Bancroft kept a house near Portman Square. No one lived there except for a small staff, as the house served more as a meeting place than a residence, except to provide an occasional refuge for Bancroft’s shadowy regiment of intelligence gatherers who needed a padded chair for an afternoon or a bed for the night.

  “You have business to conduct, Holmes?” he asked once she had settled down next to him.

  The rules of Society being what they were, he and Holmes rarely found themselves alone and in physical proximity. A hansom cab could theoretically hold three stick-thin individuals, but as she had never been stick thin, the spread of her skirt touched his trousers, provoking unmistakable sensations up and down his nerve endings.

  “I may have business to conduct, depending on whether I locate the necessary resources. Or it may turn out to be nothing.”

  He glanced out the window. The woman with the perambulator was gesturing at a hackney for hire that had been parked at the edge of the street. The hackney turned itself around and was now fifty feet behind them.

  Holmes must have noticed his preoccupation but asked no questions. Indeed, why ask questions when she could draw her own, frequently more accurate conclusions at a glance.

  He had never told her how unnerving it was to be so transparent before another, especially someone who was, most of the time, as opaque as a brick wall.

  The nearest intersections to Mrs. Watson’s house were in the shape of elongated X’s: The roads in the vicinity met at haphazard angles. To turn south and head in the direction of Portman Square, the cab would round one of those ship’s-prow-shaped junctions, which would put them out of sight of the hackney for half a minute or so.

  Lord Ingram instructed the cabbie not to make the turn on Upper Baker Street—that would put them too close to Sherlock Holmes’s address, which might be watched, too. The cabbie drove a little farther west and coaxed his mare left. The moment they were shielded from view of the other carriage, Lord Ingram tapped his walking stick against the top of the cab. “We are getting down here.”

  He tossed the cabbie a coin. “Head for Piccadilly.”

  Streets approaching one another at acute angles meant that town houses along their lengths also met like two sides of a wedge, with only a narrow opening for the carriage lane. They slipped into the carriage lane and were immediately hidden by houses that faced the street.

  He allowed them to emerge once he was certain the hackney had passed, still following the now-decoy hansom cab. They walked to the intersection, hailed the next vehicle for hire, and made for the house near Portman Square.

  The vehicle happened to be another hansom cab, when he would have wished for the larger hackney. Holmes did not wear perfume, but up close, she emanated an almost imperceptible aroma of cinnamon and butter, so faint that he could never be entirely sure he wasn’t imagining it.

  “That
probably wasn’t someone following you,” said Holmes, patting her forehead with a lacy handkerchief. “You wouldn’t lead such a person to Mrs. Watson’s front door. Was the house watched then?”

  He told her about the nanny who had, forty-eight hours earlier, been a seller of boutonnieres and cigarettes.

  “A great many individuals have been interested in my movements since I left my parents’ house,” she mused, her demeanor unconcerned. “Didn’t you once tell me that Bancroft sometimes had his underlings followed by other underlings, to test their general alertness?”

  He sucked in a breath. “Have you become an official underling to Bancroft?”

  She gazed out of the window, her attention seemingly caught by the wares of a hawker who sold boiled sweets. “Not yet, but he would like me to be. You must know that he proposed.”

  He did know, as a matter of fact. It was the reason he’d wished to call on her, to gauge the likelihood that she would become his sister-in-law. A ghastly possibility, but one for which he blamed himself: He still believed that he could have stopped her scandal from erupting in the first place, even though the exact measures he could have taken remained somewhat elusive.

  “You’re considering the proposal,” he said.

  He had never known her to reject a proposal reflexively. She always thought seriously about each, then declined just as seriously.

  “I’m working through the inducements Bancroft offered.” She retrieved an envelope from her handbag. “One of which happens to be a Vigenère cipher.”

  A Vigenère cipher? Sending Holmes a Vigenère cipher was akin to gifting her a cubic yard of cake—just because she enjoyed a slice a day didn’t mean she wanted to eat only that for days on end.

  On the other hand, Bancroft could not have better signaled his respect for her abilities.

  She passed him a piece of paper. By habit he glanced behind himself—there was no window between them and the cabbie perched on the back of the hansom cab. And the enclosure that protected the passengers from the elements was more than enough to prevent eavesdropping—which was before one took into account the general din of the city in the middle of the day.

  “Do you recognize this passage?”

  He read the vaguely archaeological paragraph. “Never seen it before.”

  “It’s possible that the plaintext, too, contains a code.” She handed him another piece of paper, this time with all the L’s and O’s underlined. “If they stand for ones and zeroes, they can represent a binary number.”

  Instead of looking at the paper, his gaze remained on her a moment too long. It was all too easy, at times, to believe that she never felt anything, that inside her rib cage beat not a heart but the metronomic device of an automaton. But this was not one of those times. Today she gave off clear signals of a hunter on the prowl, quietly excited about her quarry.

  She tapped her finger on the sheet of paper, directing his attention where it ought to go. “If I separate the text into two paragraphs at the most reasonable point, I end up with two binary numbers. When I convert them into denary numbers, these are what I get.”

  512818 and 2122.

  “You’ll have to tell me their significance.”

  “I would add a zero to the beginning of the second number.”

  A zero at the beginning of the second number? But one could add a string of zeroes before any given number and not change a—

  “You mean like this?” He took out a pen and made some changes.

  51'28'18

  0'21'22

  Latitude and longitude.

  She smiled. He blinked. She was around sixteen or seventeen when she learned to smile for company, but she never took the trouble for him.

  A fortunate thing.

  Once, he’d commented on the high number of marriage proposals she had received in the course of eight London Seasons. She had replied, only half jokingly, that all the credit lay with her bosom. He, on the other hand, was of the opinion that gentlemen, while heartily appreciative of her fine décolletage, were actually besotted by something else: her quality of concentration.

  When Holmes gave her attention, she gave with such thoroughness, as if no one else mattered, as if no one else existed. The poor sod might realize, much too late, that she now knew his every last secret. But the next time he was caught in the gaze of her large, limpid eyes, even with those intellectual alarm bells clanging in his head, he still couldn’t help but feel more important, more recognized, more seen than he had ever been in his life.

  Not to mention, not every poor sod realized her powers of observation.

  Lord Ingram had witnessed, more often than he cared to recall, the expressions of marvel and bliss on the faces of men who had been the recipients of that attention. Then, when she smiled, all the inadequacies they’d ever known were swept into a great big bonfire of strength, confidence, and will to conquer.

  “Very good,” she said. “This is somewhere in the vicinity of London, if one assumes that the latitude is fifty-one degrees north. The longitude is close enough to the meridian that east or west shouldn’t matter greatly.”

  Lord Ingram also couldn’t recall the last time—if ever—she’d said Very good to him.

  “It’s my understanding that at the house near Portman Square,” she went on, “Bancroft has a store of maps, among them highly accurate ones of London marked with longitudes and latitudes to the second.”

  Caught in the gaze of her large, limpid eyes, he needed a moment to answer. “He does.”

  She smiled again. “Bancroft does have some uses after all.”

  Lord Ingram, too busy putting out bonfires, did not reply.

  The place indicated by N 51°28'18", E 0°21'22" was close to the mouth of the Thames, in the parish of Chadwell St. Mary. N 51°28'18", W 0°21'22" marked a spot near High Street in Hounslow, a small town that had once been at some distance from London, now swallowed up by that insatiable metropolis.

  Two more unremarkable patches of ground could not be found nearby.

  “Were you expecting landmarks?” asked Lord Ingram.

  Holmes walked slowly around the large map table, the hems of her skirts swishing softly. “I didn’t expect landmarks, but I was hoping for them. After all, any two paragraphs in the English language would give sufficient L’s and O’s to form binary numbers—and any number of binary numbers would result in denary numbers that resemble longitudes and latitudes.”

  She promenaded one more round, her fingers trailing along the beveled edge of the table. She had kissed him twice—upending him both times—and he still couldn’t decide whether she enjoyed human contact. But she seemed to be interested in the texture of inanimate objects: the pile of a velvet-covered cushion, the cool surfaces of a stone wall in a field, the smoothness of each individual grape in a freshly snipped bunch.

  “I suppose I had better go take a look at these places.”

  “It will be almost impossible for us to go to Tilbury and return in less than four hours,” he pointed out. “I have an appointment before then. Better we try the location in Hounslow first.”

  She did not fail to notice the pronoun he employed. “No doubt you also prefer that I don’t head to Tilbury on my own afterward, without you.”

  “No doubt.”

  When she didn’t say anything, he added, “I am not asking to insert myself everywhere you go. But this business originated with Bancroft. Should you prove correct, should there be more to this cipher than even Bancroft knows, then you would be wading into uncharted territory. And it’s only proper to take precaution when entering uncharted territory.”

  She came to a stop. “All right. I promise I won’t investigate the other location unless you accompany me.”

  A promise? And two smiles before that?

  If one disregarded the business with Roger Shrewsbury, Holmes would be consid
ered a sensible person. But her sensibleness didn’t extend to giving him any pledges—he had expected to content himself with knowing that she had heard his words of caution.

  “What have you been up to, Holmes?”

  She met his gaze. “Only the business of my clients and this Vigenère cipher. Mrs. Watson will tell you that I barely left my room this week.”

  The problem when dealing with a once-in-a-generation caliber of liar was that her countenance never lost its earnest innocence—and hers was an exceptionally earnest and innocent face. “You are up to something—you are never this accommodating. Have you found a way to siphon funds from my account to bankroll some misadventures as Sherlock Holmes?”

  “Yes.”

  An answer of serene sweetness. He shook his head. “Very well. I won’t inquire too deeply. But I know I’m right.”

  “I’m sure you are,” she said, her face bent to the map on the table. “Now shall we to Hounslow?”

  He ought to have left well enough alone.

  Another man would have been delighted to be smiled at. Another man would have been happy to have extracted a promise. But he’d had to do the uncalled-for and question why. And now the silence had descended.

  From time to time, someone at his club would complain about the wife or the fiancée who wouldn’t stop talking and he would have to restrain himself, not to say something biting—and far too revealing—about how lucky the man was.

  One could ignore aimless chatter. One could not ignore silence.

  His house was often silent, a pointed absence of affectionate speech. He had become inured to it, but it was always a reminder of the mistakes he had made, of hopes and dreams that had become as withered as yesteryear’s gardens.

  With Holmes it was different. With Holmes the silence was taut with if-onlys. With hopes and dreams he dared not indulge in, not even in the secrecy of his own heart. Because he was a married man. Because that was an unalterable reality. And because he was afraid to find out that he had read her completely wrong.