The beating of my heart was thunderous. But like I’d done so many times since we’d arrived in Rhinebeck, I let myself stretch. I cupped my hand over the mixture and pressed down hard. The cold feeling went deep into my palm. I didn’t know if I should close my eyes or concentrate but suddenly, the muscles in my hand felt like they were being ripped apart. The pain was blinding and I snatched my hand away, but something had already happened in the dish. The silver liquid had dissolved the wolfsbane root.

“What’s going on?” I asked.

The viscous liquid turned over on itself, giving off a warm glow. He sighed, letting his shoulders fall, and clasped his hands together in front of him. “You’ve done it.”

“Done what?”

He carefully transferred the mixture back into his vial and stuck it in his pocket. “The true test will come in a week’s time. I’ll stop back and let you know if it was successful.”

“If what was successful?” I was so confused. “Wolfsbane is lethal. Whatever that liquid is, it’s dangerous. What are you going to do with it?”

“I will handle it with the utmost care. You have my word.”

Mom and Mo poked their heads into the shop.

“Everything good?” Mo asked.

“Yup,” I said.

Isaac turned to leave but paused at the door, glancing back over his shoulder. “Do guard your secrets carefully. When you can do something well, there will always be those who wish to take advantage.” He pulled out a small white envelope and set it on the counter. “I’ll be seeing you again soon. Take care.” He turned and left.

“How’d it go?” Mom asked, glancing down the hall. “Did he buy anything?”

“Yeah,” I said. I looked at my still-aching hand. “He’s an alchemist.”

“An alchemist?” Mom asked. “What’s that? Is that like a wizard?”

“Maybe?” I wasn’t really sure.

Mo came over, picked up the envelope, and peered inside. “Holy shit!” She pulled out several crisp one hundred–dollar bills.

Mom snatched the envelope. “What is this? Are these real? What did you give him?”

“Just some brimstone,” I said.

Mom and Mo stared at me.

“I know how it sounds but this place is going to serve some . . . unique clientele.”

“Like that girl, Marie?” Mom asked.

Marie was unique but probably not in the way Mom was hinting at. “Like Marie and that lady I met in town, Lucille. Dr. Grant’s pops bought something from us, and he’ll come back to buy more. We just gotta keep an open mind about the kind of people who might show up.”

Mom tucked the money back in the envelope. “Not gonna lie. I don’t like the way that sounds, especially after what happened before with the man out back. Remember him? Pawpaw Machete?”

Mo chuckled. “You’re overthinking it. It’ll be fine.”