Page 8 of Atlas of Unknowable Things

The final book, though, was absolutely extraordinary.

It was gorgeous, with exceptionally supple pages, the softest parchment I’d ever touched.

Inside were the most glorious drawings of plants, rendered in vibrant, almost succulent color.

And the edges! Marked with curlicued filigree, they were works of art in and of themselves.

I’d perused rare manuscripts plenty of times before, but there was something altogether different about this—it bordered on a religious experience.

Paging through it, I was surprised to find that while it was mostly composed in Latin, there were also elements of a different, much older-seeming language as well.

Interspersed in the text of what appeared to be a bestiary was a mixture of curious diagrams, illustrations, and maps.

I was reminded momentarily of the Voynich manuscript, that inscrutable fifteenth-century codex, the mysterious contents of which served as a perennial topic of debate in academic as well as occult circles, but this wasn’t the Voynich or any manuscript of which I was aware.

I wanted to linger over the text, but herbology called.

With a heavy heart, I returned the book to the shelf, but I told myself I would revisit it when I had the time.

In the Joan of Arc–Gilles de Rais letter, a blurry screenshot of which I had on my phone (retrieved from a digital archive), Gilles de Rais wrote about an arcane magical text that he believed contained an alchemical recipe for immortality.

It wasn’t clear what that recipe was, but he did note three ingredients: petales d’aconit, racine d’angélique, and sangdhuppe—aconite, angelica, and a third, unknown substance.

Despite my best efforts, I’d been unable to uncover anything about this rare text, but if sangdhuppe was in any of the pharmacopoeia, then I might be one step closer to proving that Joan of Arc and Gilles de Rais were actually members of a witch cult, potentially proving that witch cults were real. Take that, Charles.

After searching around in the back, I selected a stack of herbal texts, spread them out on the desk around me, and got to work.

None of them contained any mention of sangdhuppe, but where the other herbs were concerned, they were definitely illuminating.

For instance, I knew that angelica had been used in traditional medicine as a “woman’s tonic” for centuries and that it treated a variety of symptoms associated with painful and irregular menstruation.

It was still considered an effective medicinal, most likely due to the phenols, terpenoids, and phytoestrogens it contained, but what I found in the first few herbal compendiums I consulted was altogether unexpected.

They focused on angelica’s magical properties as opposed to its healing properties.

For instance, one text, Isak’s Language of Hermetic Plants, noted that it was the herb of choice for hexing gossiping women, and another claimed it was used primarily to break curses.

I encountered similar results when I looked into aconite, which though highly toxic was used in trace amounts as an analgesic in various traditional medicines.

In these texts, though, it was considered a sacred herb and was mostly used to communicate with the inhabitants of the underworld.

It was looking like my residency was going to be much more useful than I’d expected.

No sangdhuppe so far, but then a thought occurred to me.

Might this be another name for some kind of metal?

Nothing about Gilles de Rais made me think he could be an alchemist, and the process of mixing aconite and angelica was pretty far removed from turning metal into gold, but he had used the term alchemical when describing the recipe, so perhaps it was more of a substance than a plant.

Referring to non-plant matter as herbs wasn’t unheard of.

Traditional Chinese medicine practitioners, for instance, had long used oyster shells as part of formulas to “calm the spirit,” and in small doses, the velvet from discarded deer antlers was used as a yang tonic.

But that got me thinking. Maybe I was going about this all wrong.

Maybe I needed to consult a book of herbal formulas instead of combing through single herbs.

I was just about to get up and go in search of such a text when I noticed an elegantly dressed woman standing in the doorway to the scriptorium.

“Find something interesting?”

She was fashionably tall, and she wore a blue suede pencil skirt with high leather boots.

Her purple blouse was sleeveless and silk with a ruffled collar, and she wore her medium-length golden hair in waves that gave her an unexpected innocence.

She was hands down the most gorgeous woman I had ever seen.

“I’m Lexi Duarte,” she said with a charming smile as she strode over and offered her hand.

Awestruck, I stood and shook it. Staring up at her, I was reminded of the one time I’d been around an actual model, feeling minuscule and insignificant in comparison.

“I’m so glad you’ve come to use our library.

” She had just a hint of an accent, and her dark eyes held my gaze an uncomfortably long time, almost as if searching for something in particular.

Those eyes were odd, seemingly filled with emotion, though the precise emotion I would be hard-pressed to name.

“It’s wonderful you were able to join us for the summer.”

She was staring at me intently as if searching for something very important. Her breath was even a little ragged, as if she had just exerted herself.

“Dorian tells me you’d like a tour of the grounds,” she said with a tense smile.

“That would be fantastic.” I started to pack up my things, but an elegant flick of her wrist seemed to communicate that there was no need. I could leave my things here. It was that kind of a place.

I followed her up the stairs to the main library, and as we walked, I couldn’t help but notice a tension between us, as if an alarming degree of electrical energy was circulating between us, repelling us almost like magnets.

The grounds were even more lavish than I had been able to discern from my bedroom window, and the air was so fresh and crisp it made me feel newly alive.

We strolled along the paths, through the full color wheel of flowers: the arching birds-of-paradise, the fluttering lantana, the wisteria-heavy trellises.

It was like a bejeweled wonderland, a monumental garden fit for royalty.

After leading me down a flight of stone steps, Lexi walked me along a gravel path that led to the lake, that little island sitting at the center of it like a lonely beauty.

The water was a brilliant blue with an opaqueness to it that struck me as odd.

A short pier jutted out over the water and toward the island on jagged-looking wood pilings, a section of which had been worn away as if something had been repeatedly tied to it, but there was no boat in sight.

“You’re welcome to come down here as much as you like—we find it’s a good spot for meditation—but I’m afraid…”

“Right, no swimming. Dorian told me. Too cold.”

“Actually, it’s environmental,” she said with a tilt of her head. “There are several species of endangered fish, and of course you can see by the color that the ecosystem is quite delicate. So we ask that you don’t put so much as a toe in. And the island is off-limits.”

“That’s why you removed the boat?”

She nodded gravely. “We had an incident.” She clapped her hands, her mood shifting abruptly. “Now let me show you the apothecary garden.”

As I followed Lexi down a side path that led to the same brick walkway I’d traversed the previous night, anxiety rose in my belly.

I hadn’t wanted to mention my night excursion to anyone.

I’d never experienced sleep paralysis or sleepwalking before, and it wasn’t like it was going to happen again, so I didn’t want to call attention to it, but now that we were here, I suddenly felt like an interloper.

I didn’t know much about how sleepwalking worked, but I’d read that people could do all kinds of things during an episode, even drive a car.

Some part of me must have been conscious enough to leave the house and find Casimir’s cabana, but why?

Was I so desperate to find the relic that my subconscious had begun acting as a free agent?

I’d read some about somnambulism and knew that people were actually capable of committing crimes while asleep.

There had even been cases of sleepwalkers being acquitted of crimes because they were afflicted with what was called non-insane automatism due to somnambulism.

But the question remained: Even if a person’s conscious mind had no desire to commit that crime, was it possible that they were spurred into action by a subconscious drive so strong that although it could be repressed during waking hours, it couldn’t be contained during sleep?

Not that I had committed any kind of crime, I told myself as I stood there, beads of guilty sweat nonetheless beginning to form on my brow.

In the light of day, the cabanas lined up alongside the path had a bright Caribbean feel to them, the blue of their wooden shutters bringing to mind pineapples and tropical breezes.

As we passed one, I could hear laughter trickling out from between the blue shutters, and for a moment I thought I recognized one of the voices.

“Some of the faculty housing is down here. Hildegard College is unique in that…”

Lexi stopped suddenly and stared at the front door of what I now realized was Dr. Casimir’s cottage.

“That’s strange.”

She strode up the flagstone path to what I now saw was an open door. Panic surged through my body. Had I misremembered the night before? Had the door actually been unlocked when I tried it? Cautiously Lexi opened it and stepped inside.