“Your roommate. You said. A pleasure to meet you, Ms. Daye.” May looked surprised but pleased as Walther tucked the vial into his pocket, turning his attention back to me. “I only got here a few minutes ago. Did you drive the whole way invisible?”

“Yeah, we did. It’s faster. Sort of.” I took Spike from May, holding it toward Walther. “This is Spike.”

“The rose goblin? Marcia mentioned things might get odd around you.” I gave him a quizzical look. He shrugged. “I asked her to fill me in on what to expect when I started working with you.” Quickly, he added, “You were right; it doesn’t look healthy.”

I decided to let Walther’s digging into my background slide. I would have done the same thing in his shoes. “It was fine until Luna got sick.”

“May I . . . ?” He reached for the goblin.

“Be my guest.” I passed Spike to him, wincing as I saw how shallowly it was breathing. I wasn’t sure it actually needed to breathe—it was as much plant as animal—but that didn’t mean good things would happen if it stopped. May settled beside me, shifting her weight uneasily from foot to foot. I put a hand on her shoulder, and waited.

Walther cradled Spike against his chest, listening to its breathing before putting a finger on its throat to test its pulse. Finally, he said, “This is a very sick goblin.”

“We know. That’s why I want you to take soil samples here.”

“Because of the connection between the Duchess and the goblins?”

I nodded.

To my surprise, he chuckled grimly as he passed Spike to May. “Faerie never fails to stay interesting, does it?”

“Like a Chinese curse,” I said. “Let’s go find some roses.”

We didn’t have to look for long. The bush was half-dead, its few surviving flowers liberally mottled with brown. I stopped. “Here’s one.”

“Got it.” Walther pulled a spoon out of his pocket and knelt to dig around the roots of the bush. He stopped after only a few seconds, frowning. “That’s not right.”

“What isn’t?” May asked.

“The texture of this soil is all wrong.” He pulled a small jar from his coat pocket, dumping a spoonful of dirt inside. Then he uncapped the vial he’d been studying when we arrived, pouring its pale red contents into the jar. The resulting mixture fizzed and turned clear. Walther’s frown deepened.

“I don’t like that look,” I said. “What’s wrong?”

“There’s no poison here. Something’s still not right.” Walther waved his hand over the jar, muttering in Welsh. The liquid turned gold and started fizzing again.

“He’s weird,” said May. “If he pulls out a Bunsen burner, we’re leaving.”

I bit back a smile. If she was feeling well enough to be snide, we were doing better than I’d thought. “He’s Tylwyth Teg,” I said, like that explained everything.

Apparently it did, because May looked satisfied with that answer. Walther kept chanting as the liquid changed colors, finally settling on a glittering white.

“Ah,” said Walther, and stood.

I raised an eyebrow. “Talk to me. What’s going on?”

“Salt.” He held up the jar for my inspection.

“What do you mean, ‘salt’?” I squinted at the jar like I expected his words to start making sense. “Isn’t there always salt in dirt?”

“A little bit, but plants die if they get too much. This dirt has too much salt. Think of it as dosing a person with a little bit of arsenic at a time. It’s essentially slow murder.” He shook his head. “The only way to get rid of it is to leech it out, and the plant still might die if there’s enough damage.”

“Leech it? How?” I demanded. The implications were sinking in. The damned drink was a red herring; the salt was our real culprit. There could be another poison involved, something to knock her out once she’d been weakened, but poisoning the roses would be enough to incapacitate her.

“The soil needs to be flushed with water and treated with gypsum. Uh, that’s a mineral that pulls salt out of the ground.”

“How fast can we do that?”

“This isn’t something you can just snap your fingers and do. It takes time for the soil to recover, and that doesn’t take into account how long it’ll take the plant to get better.” He shook his head. “I might be able to speed things up, but it won’t be instantaneous. I’m a chemist, not a horticulturist.”

I shrugged. “You’re all we have.”

Walther paused. Then he held his hands out to May. “Give me the goblin.”

She glanced to me. I nodded consent, and she reluctantly handed Spike over. Walther pulled it to his chest, cradling it as he reached into his pocket for another vial.

“If this doesn’t work, there’s nothing else I can do,” he said, not looking up.

“I understand,” I said.

Prying Spike’s jaws open, Walther uncapped the vial and poured its smoky purple contents down the rose goblin’s throat. Spike went limp, and Walther began chanting in rapid Welsh.

May grabbed my arm, hissing, “What’s he doing?”

“Trying to save us.” I put my hand over hers. The air crackled with the scent of yarrow and the cold, bitter tang of ice as Walther’s human disguise started to waver, flickering around him like a bad special effect. That wasn’t a good sign. Everyone has their limits, and I didn’t know where Walther’s were.

I stepped forward, putting my free hand on his shoulder to steady him as his chanting took on a more frantic pace. He flashed me a grateful look, finishing his chant with a string of repeated syllables. The magic shattered, and Walther sagged into my arms.

Spike opened its eyes, making a small, bemused sound.

“Spike!” cried May, rushing to embrace the rose goblin. It chirped and scrambled onto her shoulder, holding itself in place with three paws as it started grooming the fourth.

I was occupied with keeping Walther from knocking us both over. He wasn’t a small man, and he was heavier than he looked. I wound up locking one knee and shoving, supporting him against my shoulder. “You okay in there?”

“I’m fine,” he managed, trying to stand. “Ow. My head.”