Spike landed well beyond the wide-spreading roots of the banyan tree.

Nearby, white wooden spears stabbed the ground, like the posts of an unfinished fence. They looked as though they might encircle the entire tree.

“Can’t get any closer than this,” the horse spirit said while chewing on a granola bar that Zhong was shoving into her mouth. “Inside that boundary is sacred ground. But I’ll keep an eye out and try to catch you if the arborist throws you off the mountain.”

“Um, thanks.” I left my backpack and cloak on the saddle. There was no one to recognize me here, and all our supplies fit in Zhong’s magic backpack. “What’s an arborist?”

“Protector of the Tree of Souls.”

I thought about the gardener-woman I’d seen in my dream the night after I released the bridge spirit. You’re the one who escaped, she’d said to me. Come to think of it, the bird’s-eye (horse’s-eye?) view of this place as we descended was exactly as it had been in my dream—a vista of vibrant green trees and rice paddies climbing the sides of mist-shrouded mountains.

Zhong finished feeding her horse and then wiped her hands. “It’s incredible. I’ve always wanted to see the Tree of Souls, but Master Bo said it was bad luck to come here before your time.”

“Hopefully he was wrong.”

The white cloths on the branches fluttered in a silent wind that blew across the mountaintop. When I stepped past the boundary, voices began to whisper around me. I covered my ears, but it didn’t help.

“I shouldn’t have run away.”

“I never got to say good-bye.”

“Did I leave the oven on?”

I shook my head. I was hearing the voices of souls that were bound to the tree as they waited for reincarnation. How long they lingered probably depended on the life they’d lived. Some people would be stuck here a very long time. Although not as long as Shee Yee, who was never supposed to have been reincarnated. What had happened to change that?

“I don’t like it here,” Miv said. He’d had to disentangle himself from my dress again before climbing onto my shoulder.

“Me neither.” I waved my hand around my head, like I could swat the voices away.

Zhong joined me inside the boundary, her backpack on her shoulders again. With a wary nod, we approached the tree. It looked weathered and ancient. I couldn’t help feeling a little awed thinking about how long it must have stood on this mountain. Without leaves, the tree could have looked dead, but it didn’t. I felt its presence like a living, breathing spirit.

“You said the ax is buried inside?” I asked Miv.

We picked our way through the tangle of the tree’s limbs. We had to climb over roots that both dove down and climbed up through the earth. Just trying to reach the main trunk was like going through an obstacle course.

“Deep inside,” Miv said.

“Well then, how do we get in?”

One time last summer, I’d wedged myself into a hollow trunk while pretending to be a tree spirit. It had been tight, scratchy, and kind of spooky in there. Ants had crawled up my legs. Matt had said I looked like a squashed banana and Miv, sitting on his shoulder, had nodded in agreement. I didn’t think going inside the Tree of Souls would be like that.

Except maybe the spooky part.

Suddenly, a hidden door in the banyan’s trunk swung open. A woman walked out, holding a garden hoe and wearing bright-red rubber boots. A green handkerchief covered her black hair. Her skin was a warm brown but weathered and knotted, like the bark of a birch tree.

It was the woman from my dream. Her gaze flew to ours before we could even think to hide. She shook the garden hoe at us. “Trespassers!”

She clearly had way more practice getting around the tree’s roots and branches than we did, because she crossed the distance between us with amazing speed. Miv hid beneath my hair. I exchanged a look with Zhong. Were we supposed to run away? I hadn’t been afraid of the woman in my dream, only startled, because of how strange the whole thing had been. For some reason, I didn’t think she would hurt us.

The woman paused, squinting to get a better look at me. Her eyes were watery and clear, like tree sap. She pointed one knobby, twig-like finger. “You. I’d know your soul anywhere.”

I stood up straighter. It hadn’t made any sense to me in the dream, but now I knew that she was talking about Shee Yee’s spirit. “My name is Pahua.”

“I know what your name is.” She smacked the hoe into a large root. The root sank into the earth, clearing a path for her. I gulped and stepped back. Maybe I was wrong about her not hurting us. “If you were anyone else, I’d curse you and throw you off the mountain. This is sacred ground.”

Spike had mentioned that. I wiped my palms on my dress and asked, “Are you the banyan tree’s spirit?”

She gave a single, harsh laugh. It sounded like the scrape of sandpaper. “Ha! The tree already has plenty of those, don’t you think? I’m Yeng, the arborist.”

“You care for the tree and the souls here.” I glanced over my shoulder at where Spike still waited beyond the boundary. The horse spirit was flailing her front hooves. She could have been performing an elaborate dance ritual or telling us to run away before Yeng killed us.

But I still didn’t think we had anything to fear from the arborist. It wasn’t because she wasn’t threatening looking. That garden hoe seemed pretty sharp. It was because she was a caretaker of souls. Something in her eyes reassured me. They had a warmth to them.

Also, she’d just said she wouldn’t curse me.

Yeng glared at Zhong and Miv as if deciding whether to curse them instead. “Cat spirits aren’t welcome in a waiting place for mortal spirits. As for you,” she said, gesturing to me and Zhong, “are you so eager to die? All mortal souls eventually come into my care, but few of them come so willingly.”

With that, she turned away, grumbling under her breath about trespassers, mortals without any sense, and weeds.

Zhong made a shooing gesture to indicate I should follow Yeng. The door in the tree had closed. If anyone could help us get inside, it’d be the arborist.

“Wait!” I called, hurrying after Yeng. Geez, she was fast. “Since you know who I am, then you must know why I’m here.”

“Oh, I certainly do, little shaman. You’re after the lightning ax, a celestial weapon of the gods. What destruction do you plan to unleash in this lifetime?”

We picked our way around the tangle of roots and branches, she more easily than me and Zhong, until we arrived at her garden.

“I’m not going to unleash any destruction,” I said. “I just want to save my brother.” My sandals weren’t made for walking through rich, moist soil. I waited beside a row of cabbages as the arborist continued between small bushes of red chili peppers.

She made a skeptical hmm sound. “And what about that one?” she asked, looking past me at Zhong.

My friend bowed over the cabbages and said, “I’m on a quest for my school. Our guardian spirit has always spoken well of you. It’s an honor to meet such an esteemed one.”

“Is your quest worth your life?” Yeng asked, leaning on her hoe like a cane. “If the Tree of Souls decides to levy such a toll?”

Visibly swallowing, Zhong gripped the hilt of her sword and glanced at me.

“I can go alone, if—” I began, but Zhong cut me off.

“We’ve already come this far,” she said. “My future is worth the risk. Besides, if we succeed, I’ll be the first shaman at the school to pass through the Tree of Souls while still alive. It’ll be a mark of achievement. The guardian spirit will have to take that into account.”

Yeng snorted and then abruptly stiffened. She tilted her head, listening. Her dark braid fell over her shoulder. Slowly, she lifted her hand and pulled from the air a thin strip of white cloth. It glowed a little, casting her brown fingers in soft light. She caressed it with her thumb, nodding and whispering something under her breath.

“A new soul,” she said louder, glancing over at me. “You can hear them, can’t you?”

“Hear what?” Zhong asked, looking between me and Yeng.

I nodded. The voices of the souls had been distinct at first, but the closer we got to the main trunk, the more the voices began to blur into an unintelligible hum. There were simply too many of them to make out.

“That’s a rare gift,” Yeng said. “But unsurprising for Shee Yee, who was favored by the Sky Father. Where should I place it on the tree?”

The question surprised me. I looked up. Every visible branch was covered end to end with white cloths. So many souls, so many stories, so many regrets. And Shee Yee had been stuck here for four thousand years. “I wouldn’t even know where to begin.”

Yeng’s mouth twisted into a mocking smile. She held the cloth up to the tree. The branches creaked and groaned as they parted, revealing a smaller branch lowering itself to meet her short reach. She passed her fingers over the white cloths already tied to the branch. I flinched as the din of their voices flickered through my head. I couldn’t catch any words, but I felt enough of their pain and regret that I didn’t want to know what they were saying.

“Some spirits fall from the tree on their own when they’re ready, like leaves in autumn. Others must be coaxed.” She rubbed the end of one cloth between two fingers, considering. “This one has been here awhile.” She leaned her ear close to the cloth. Her eyes grew glassy as she listened. “Petty thievery, lying, never changing the toilet-paper roll. You can go, I guess.”

She gave the cloth a gentle tug. It instantly unraveled from the branch. After inhaling deeply, she blew the soul from her hand, releasing it to the wind. Within moments, it vanished, and she tied the new one in its place. When she was finished, the branch returned to its original position, high out of sight.

There were so many questions I wanted to ask her. Right now, though, there was only one answer I needed. “So, can I have my ax?”

She gave that bark of laughter again. “Oh, you can have it. If you can get to it. Can you face your own soul, Pahua Moua?”

“What does that mean?”

Ignoring me, she turned to Zhong. “Make sure your quest is worth it. Are you certain you’re meant to be a shaman warrior?”

For a heartbeat, doubt flickered over Zhong’s face. Then that familiar superiority settled over her, and she nodded firmly. “I am. Whatever it takes.”

Yeng clucked at the tree. Another hidden door swung open. A set of stairs made of roots descended into darkness. Why did it always have to be darkness? Why couldn’t it have been a tunnel full of daisies and sunshine? In my pretend adventures, I always liked imagining dangerous stuff—labyrinths full of monsters, goblin caves with booby traps, flesh-eating plants that spit venom. But those things were a lot less fun in real life.

“I don’t suppose you have a map?” I asked.

Yeng tapped the side of her head and gave me a grin that didn’t seem entirely sane. “Nope, it’s all up here. But I guess I can give you this.”

She pulled at a chain around her neck that I hadn’t noticed before and drew the necklace over her head. At the end of it hung a flat silver locket the size of her palm. She opened it, revealing a single vivid green leaf. Without a word, she held out the locket to me.

I accepted it, waiting for an explanation. The leaf was glossy and leathery, its shape long and rounded.

“That is the only leaf the Tree of Souls has ever grown,” Yeng said. “It will help get you where you need to go. Or, if nothing else, it’ll prevent the tree from swallowing you.”

I tried not to gulp at the way she smiled when she said this. It was just a leaf, after all. Before I could thank her, she turned away to lean over her chili peppers.

“Does the leaf turn into a boat?” Zhong asked.

“Why would it do that?” I put on the necklace, tucking the locket with the leaf inside the collar of my dress.

Zhong shrugged like that hadn’t been a totally random thing to ask. “Because, you know, the story about how the Hmong ended up in Southeast Asia.”

“No?”

“Geez, Pahua. Didn’t your mom teach you anything about our mythology?”

“She taught me plenty! But what does that have to do with a leaf?”

“The Hmong originally lived in China, but when they were persecuted for not fitting in with the culture, they had to migrate. A great shaman created a boat from a pile of leaves, and a benevolent spirit blew a powerful wind that carried them south into what’s now Laos and Vietnam.”

“Oh. That’s cool.”

Zhong looked annoyed, like she’d expected a more enthusiastic reaction. She nodded toward the open door. “Come on, then.”

I hesitated. Yeng was still crouched over her peppers, picking off the bad ones and tossing them over her shoulder. Tiny nature spirits ran screaming from the garden. She cackled in delight.

“Excuse me,” I said, approaching her cautiously. “Can I ask…How did you lose Shee Yee’s soul? Didn’t the gods want him bound to the Tree of Souls forever?”

She lifted her head to glare at me. The bark of her forehead puckered, peeling in one spot. When she spoke, it was in a furious hiss. “It wasn’t me. A trespasser entered this sacred ground and laid hands upon the branches.”

“Where were you?”

She snarled. “In my weekly yoga class. It’s not easy staying limber when you’re made of wood, you know.”

“So, someone just stopped by and pulled his spirit free? Just like that?” I asked, looking up at the cloths.

“Don’t be an idiot. If it were that easy, human souls would be flying all over the place and making a nuisance of themselves. Shee Yee was magicked free with a power greater than my own.”

That sounded pretty worrying. Power greater than the arborist’s? “But whose?”

“That’s the million-dollar question, isn’t it?” she said, and spat a wad of sap into the dirt. I tried not to gag. “Get going. Aren’t you supposed to be short on time?”

“Right. Thank you for the leaf,” I said, giving her a quick bow.

She cackled. “Don’t thank me yet, girl.”

Feeling unsettled, I joined Zhong by the doorway. Miv, who was still curled into a ball on my shoulder, whispered, “I don’t think she’s all there.”

“Looks like we’ll have to find the ax on our own,” I said to Zhong. Maybe there would be a sign inside. FOR DEFEATING VENGEFUL GODS AND PESKY BRIDGE SPIRITS, AND FOR SUPER-SPEEDY WOOD-CHOPPING, CHECK OUT THE CELESTIAL AX IN AISLE 12.

“I’m right here with you,” Miv said.

I smiled gratefully, some of my worry fading. Miv wasn’t the best at delivering motivational speeches or saying nice things in general. But like Matt, he’d always been there for me, for as long as I could remember. He gave me confidence. “Thank you.” I looked at Zhong. “You, too.”

Even though Zhong’s ears turned pink, she rolled her eyes and handed me the flashlight. “If you two are done being mushy, let’s get this over with.”

“Right.” I shone the light before us. It didn’t reach very far. The bottom of the stairs was still shrouded in complete darkness.

Right, I repeated to myself. I was a daring treasure-hunter searching for long-lost gold. I was a warrior archaeologist on a dig for an ancient artifact.

With a nod, I descended into the tree.