I finally pulled the canteen away and wiped water from my lips with a long edge of my skirt. “Do you often go onto other people’s farmland to get what you need?” I thought not only of this shed, which did not belong to us, but the field where we’d just spent almost an entire night.

She shook her head. “Almost never. The wild, uncultivated earth provides most of what I need, and she disguises well her poisons. You have seen a belladonna bloom, yes? It opens like a cocoon. It seduces, almost. It may seem rare and unusual, but the truth is that this sort of thing may be found everywhere. The earth knows the secret to disguise, and many would not believe that the low fields they tend, or the trellis vines under which they kiss, hold poison within their stems. One only need know where to look.”

I glanced at the hay bales against which we sat, wondering if Nella had some trick, possibly, to extract poison from something as innocent as dried grass. “Did you learn all this from books?” In her shop, I had seen the stacks of dozens of books, some appearing worn and well used, and I began now to feel foolish for broaching the idea of a short apprenticeship. It must have taken her years to learn everything she knew.

Nella took a bite of cheese, chewing slowly. “No. My mother.”

Her words were sharp and uninviting, but this only served to pique my curiosity. “Your mother who did not have the wall or poisons.”

“That’s right. As I’ve said, a woman does not need to hide behind a wall if she has no secrets and does no wrong.”

I thought of my mistress and myself, sitting in the drawing room behind a closed door, pretending to write letters, while Mr. Amwell suffered upstairs.

“My mother was a good woman,” Nella added, letting out a shaky breath. “She did not dispense a single poison in her lifetime. You may have noticed it while looking through the older entries in my book tonight. The older remedies are helpful, curative. All of them.”

I sat up straighter, wondering if Nella might finally share her story with me. Bravely, I ventured the question. “If she did not dispense poisons, how did she teach you about them?”

Nella looked hard at me. “Many good remedies are poisonous in great quantities or when prepared a certain way. She taught me these quantities and preparations for my own safety, and for the safety of our patrons. Besides, just because my mother did not use poisons against anyone does not mean she did not know how.” She nestled farther into the hay bale. “I suppose this made her even more admirable. Like a dog with a mouthful of sharp teeth who never once attacks, my mother’s knowledge was a weapon she never once used.”