“I would argue there is no difference at all,” Thornhollow said. “To me the insane are simply people who have chosen not to participate in the world in the same manner as the majority, and there are days I wonder if they’ve got the right of it.”

“You make it sound as if hardly anyone is insane with a definition as narrow as that.”

“Quite the opposite; my definition is too broad. I think we’re all quite mad. Some of us are just more discreet about it.”

“Surely there is such a thing as true insanity?”

“There is,” Thornhollow said reluctantly, “but I would argue those cases are much fewer than most suspect. These walls exist for a reason, but there is no cause for there to be so many rooms inside.”

“Nell doesn’t belong here,” Grace said, almost to herself.

“Certainly not,” Thornhollow agreed. “There’s nothing wrong with the girl mentally. Physically . . . well, perhaps she hasn’t told you.”

“Elizabeth said she’s a syphilitic.”

“That’s correct.” The doctor nodded. “Which means she receives mercury baths on a regular basis, but that’s something a physician could administer as easily as asylum staff. The true reason for her being admitted here is that she is a young woman who takes an active interest in men and feels no shame in it. The world can’t understand this behavior; therefore the girl must be insane.”

“And Elizabeth? She believes a string dangles from nowhere beside her ear and whispers things to her.”

“Highly unlikely. Janey told me that she sees little Lizzie hovering in doorways often. I think she’s highly attuned to detail, much like yourself. She gleans information from people, then picks up some like any busybody. But in her mind she attributes it all to String.” Thornhollow shrugged. “Then again, I could be completely wrong. Who’s to say String isn’t real?”

“I can hardly agree with that,” Grace said. “I like her quite well, but there’s clearly something wrong with—”

“With her brain?” Thornhollow interrupted. “What would you say, then, if I told you that I’ve dissected hundreds of brains—of both the sane and insane—and found no difference whatsoever in them?”

“None?”

“My brain, and yours, Elizabeth’s, Heedson’s, even our mutual friend Falsteed’s would all look the same if we ever had the opportunity of comparing them. It’s one of the reasons why I have no use whatsoever for phrenology.”

Grace stifled a yawn. “I’m afraid I’ll have to ask you to explain what phrenology is, Doctor.”

“No, no. Don’t let me keep you up. I tend to go on once I’ve got my teeth in a subject, and sometimes I forget that my audience may not be as keen as I am on the matter of dissecting brains.”

Grace glanced at the clock. “Explain phrenology, and then I’ll take myself to bed. I don’t mind being kept up when it’s the only time I am allowed to be myself.”

“Very well.” Thornhollow returned to the board and drew a caricature of a human head, dividing it into uneven sections with a few slashes of the chalk. “The idea behind phrenology is that the brain is divided into certain parts, each part with a specific purpose. Within these parts are smaller areas that control certain functions that determine your personality.” He made smaller crosshatch marks within the sections.

“So, for example, in a particularly brave person the part of the brain that handles courage would be overdeveloped. That section would be larger than others, pressing against the skull and reshaping it to create a subtle bump there. The theory is that a person trained in phrenology—as I am—would be able to feel the bumps and ridges of a person’s skull and intimate from them what their characteristics are.”

“That’s utterly ridiculous,” Grace said. “I’d sooner ask Elizabeth’s string.”

“And get a more accurate reading,” Thornhollow agreed.

“Yet you are trained in this pseudoscience. Why?”

“Because there are those who swear by it. I’ve gained access to a few killers for some stolen moments of questions by offering my services as a phrenologist to law enforcement. Although the vast majority of the people whose skulls I’m brought in to read are thoroughly innocent and utterly terrified of being proved otherwise.”

“And what do you do then?”

“Gather information from them, once they’re calm enough to provide it. Analyze the facts, starting with the first and largest step—the one I’ve taught you tonight. As with our made-up killer who planned his crime and dumped the body somewhere familiar to him, I use the crime to paint a portrait of the killer. When faced with an accused innocent, the best possible defense is to find the guilty.” Thornhollow wheeled back to the board, pointing at the series of words he’d written. “That one who . . . I spelled sibling wrong.”

Grace smothered a smile with her hand.

“It’s all very well for you,” Thornhollow said irritably as he wiped the offending word away with his sleeve. “You don’t have to be concerned about your intellect slipping.”

“I very much doubt yours is slipping,” Grace said as he flung himself into a wing chair. “You are simply overtired, as am I.”

Thornhollow tented his hands over his eyes. “That I am. I can’t serve my new patients if I don’t know anything about them, but their histories make for long and occasionally disturbing reading. What about yourself? How are you finding your new residence?”

Grace thought for a moment, aware that she could never verbalize the feeling of safety that enveloped her as she slept, the ease of companionship she found even among those who could only stare blankly. “I am content,” she said.

“Ah, contentment,” Thornhollow said. “A wholly underrated feeling.” His suddenly blank gaze was drawn back to the floor. “Go to bed, Grace. I’ll wake you if there’s a murder.”

EIGHTEEN

There was no murder. Not that night, or any of the following. Days stretched into weeks, the fine webbing of skin that knit itself into scar tissue on Grace’s temples softening into a smoothness that her fingers sought out for comfort or while in thought. As a child she had sucked her thumb, and the habit had been hard to break. Her mother had scolded her about ruining the shape of her mouth, but the threats of the future had been nothing against the terror of the present, and young Grace had found solace in the action while harsh words crept down the hallway from her parents’ room.

In truth, she could easily resort to sucking her thumb again, Grace thought while helping Nell in the garden. No one in the asylum would care at all, shape of her mouth be damned. But touching the smooth flesh of her scars brought its own kind of comfort, and the movement itself became an involuntary action when she was deep in thought. The doctor had noticed during their weekly lessons and hadn’t discouraged it.

“The movement may help you recover information,” he’d said, the third time her hands had gone to her temples the night before.

“What?” Grace jerked her hands down, distracted. The chalkboard had been cloudy with words: new theories vied for space against old ones, with Thornhollow’s opinions sprinkled liberally between them.

“Touching your scars,” he explained. “If you perform an action while learning something, re-creating the action may help you recall it later.”

Her fingers went to them again as she worked beside Nell, heedless of the dirt on her hands. Visually she could recall scenes in intricate detail, but to catalog theories and counterarguments as to their usefulness was a different animal altogether, and she wanted to tame it.

“Sometimes I can’t keep me ’ands off meself, either, though I’m not usually ’avin’ a go at me own ’ead,” Nell said, playfully bumping hips with Grace.

Grace pushed back gently, winning a smile from the Irish girl. “You’ve gone an’ muddied up that nice skin of yours,” Nell chided, licking her own thumb and rubbing Grace’s face clean. “Don’t want a pretty lass like ye lookin’ like a field hand when your doctor comes around.”