If she were writing the cipher, this would be the point at which she chose a keyword.
To encode the sentence CHARLOTTE IS SHERLOCK, with the keyword HOLMES, she would write the following:
CHARLOTTEISSHERLOCK
HOLMESHOLMESHOLMESH
In coding the first letter C, one consulted column C, row H of the tabula recta. The next letter was to be found at the intersection of column H, row O. The process was repeated as many times as there were letters in the original message. In the end, the cipher text would read:
JVLDPGAHPUWKOSCXSUR
But since someone else had chosen the keyword for this cipher, Charlotte must first find out what it was. She examined the huddle of letters that formed the cipher text, looked for repeated sequences, and counted the number of letters between each iteration of the same sequence—to help determine the length of the keyword.
By the stroke of midnight, her temples throbbed. Mr. Babbage, in fact, had turned down the opportunity to decipher King Charles I’s coded letters—probably because his head still ached from the Vigenère ciphers.
She rose and walked to the window. Almost immediately she saw Lord Ingram in her mind’s eye. Winter, two months after his wedding, at a house party in the country. She had come upon him outside, on a snow- and mistletoe-draped terrace. He had been smoking, his head tilted back, blowing a leisurely stream of smoke into the air.
His eyes had been closed—and he had smiled at the overcast sky. At what he believed to be a benevolent universe.
“Hullo, Holmes,” he said, his shoulders relaxed, his eyes still closed, and a trace of smile still on his lips. “Aren’t you going to ask me how I knew it was you?”
“You’d tell me because no one else would stand here without saying anything.”
He laughed and opened his eyes. “It’s you all right, Holmes.” He took a drag on the cigarette. “You look different. Have you lost weight?”
She had. “No,” she said. “You look happy. Marriage must agree with you.”
“It does indeed.” He was magnanimous in his happiness, refraining from reminding her that she had warned him against this particular match. “You should give it a try.”
He and his wife had come back only a few days ago from their honeymoon, their return more than a fortnight late. They had arrived at the house party in the afternoon but had not made an appearance at dinner. Lady Ingram was said to be a little under the weather.
Charlotte felt as if she had been harpooned. “You’re going to be a father, aren’t you?”
Present-day Charlotte turned away from the window.
It was the most joyous she had ever seen him. She’d never trusted that joy, but to look back, knowing exactly how false its foundation had been, how ephemeral its soap-bubble brightness...
She marched back to the desk and reimmersed herself, almost gratefully, in the mind-pulverizing tedium of the Vigenère cipher.
Six
MONDAY
Livia didn’t mind music. But she would enjoy a soiree musicale much better if she could dance—or read. Dancing, however, was not to be had, and reading would be profoundly frowned upon. So she had no choice but to listen, bored, irritated, and worried—her usual state of mind—as the soprano warbled on.
When the broad Italian woman hit another glass-scratching high note, Livia simply had to get out. She had taken care to sit in the back of the drawing room, at the edge of a row of chairs. Her mother glared at her as she rose. Livia headed toward the cloakroom—she didn’t need to use it, but Lady Holmes would be less likely to follow if she believed Livia had gone to answer a call of nature.
When she was far enough from the drawing room, she leaned against a half pillar in the passage. Whose house was she in? Oh, what did it matter? The Season was drawing to a close. Soon London would empty, and Livia would take part in the exodus.
Usually, by this point in July, despite the disappointment of having once again failed to secure a husband, she would be more thanready to return to the country, so as not to be obliged to constantly smile, nod, and make pleasant conversation, in a futile quest to prove herself worthy of that holy grail, matrimony.
But this time Charlotte would not be coming with her. This time she would truly be all alone.
At the sound of approaching footsteps, she straightened hastily. A woman turned the corner from the direction of the cloakroom. Lady Ingram. She had arrived late to the soiree, after the first piano recital had already begun. But the hostess had been overjoyed to see her and had hovered about her for an indecent length of time.
Lady Ingram appeared equally startled to run into Livia. “Miss Holmes.”
“Lady Ingram.”
