The next morning I dressed in a practical dress and my most comfortable boots. I had been working on my physical fitness ever since I got swept up in my older sister’s spy network at the age of fourteen, but those mountain roads looked steep. I didn’t want to disgrace myself.

I had slept badly. Once alone in my room, I tried to call on my new powers, but all my efforts to expel light or heat or wind from my hands ended in failure. And then my dreams had been haunted by the many different faces of the unexpected Prince Oliver. By the time I awoke, I was entirely uncertain which prince would greet me today.

But when we met in the entrance hall at mid-morning, one glance was enough to tell me that none of his new fire had dimmed. His eyes were bright and the aura of strength which I had seen for the first time only the night before remained.

Something in his eyes flashed at the sight of me, and he smiled, coming forward to greet me warmly.

“I’m glad to see I didn’t frighten you off last night.” He bowed over my hand.

I raised an eyebrow. “I’m not so easily scared, I assure you, Your Highness.”

“Oliver, please,” he said. “I remember enough to know that’s what you were calling me before, Celine.”

I shook my head at his bold use of my own name and conceded the point. I didn’t want to admit to him that I felt as if I were dealing with an entirely new person.

He led me out of the palace and around behind it. The palace wall only encircled the front and sides of the building, blending almost seamlessly into the mountain itself which guarded the rear of the palace. A steep road, wider than I had been expecting, zigzagged up the mountain, starting from the very back of the palace. A number of people traveled it, some pulling small carts, others leading slightly bigger carts pulled by goats. When I gazed upward, I even saw a lady being carried on an elaborate chair mounted on two long poles. The poles rested on the shoulders of four strong men, dressed as footmen in a livery I didn’t recognize.

Oliver followed my gaze. “It’s not too late if you would like me to fetch a chair for you.”

I grinned. “I’m no more feeble than I am easily scared. Oliver,” I added for good measure.

He laughed. “I suspected as much. In that case, let us be off.”

I needed every bit of my conditioning to keep from puffing as we wound our way up the mountainside using a maze of roads and stairs carved into the rock face. I could only be glad so many months had passed since my broken ankle, and that I had lost no time in regaining my shape once it healed. Oliver certainly showed no discomfort despite the steep inclines.

We passed every type of business from blacksmiths and grocers to tanners. Several roads were lined with shopfronts, replacing the more traditional market squares. They looked like normal buildings from the front, except they were so close to the mountain face it didn’t seem there could possibly be room inside to move, let alone store any goods. But I soon saw that it was just as Oliver had told me when we arrived. The shops stretched back into the mountain itself, looking remarkably like an ordinary building from the inside except for the solid stone walls and lack of windows.

As we got higher, we found a number of noble residences, some of them using the same stone as the palace to decorate their facades. I supposed they could afford to position themselves higher up the mountain if they had servants to carry them up and down in chairs.

“Isn’t all of this snowed in during the winter?” I asked, as we wound through a less affluent section of the city where the building fronts crowded close together and contained little ornamentation. Some were no more than wooden doors and shutters over what looked like cave openings.

“This is one of the smallest mountains and is right at the foothills of our main range,” Oliver explained.

It didn’t look like a small mountain to me, but I hoped my face didn’t show my incredulity. Mists mostly obscured the far distance, but they had parted once to show me a glimpse of higher peaks behind.

“We get snow, of course,” he continued, “but not normally so much that it cannot be cleared from the roads. And with most of the buildings inside the mountain itself, even in the case of a heavy snowfall or avalanche, the people are out of harm’s way.”

“But wouldn’t they be trapped inside?”

“We have lived here for many generations now,” said Oliver. “All of the buildings connect to at least one tunnel. When the weather is truly bad, the palace can be cut off for several days, but the inhabitants of the city simply use the internal roads.”

The idea fascinated me, but I also hated the thought of going days without seeing the sun. Something of my distaste must have shown on my face because Oliver grinned.

“Yes, most people prefer to use the open roads if the weather possibly allows. Especially the nobles, since some of them keep horses up here, and the horses hate the tunnels.”

“It’s an incredible place,” I said. “I never imagined anything like it.”

Oliver looked around, pride in his gaze as he surveyed his city. “You can’t imagine my surprise as a child the first time I visited a flat city. I didn’t know what to make of it and kept asking my mother what happened when it snowed too much to go outside.”

He laughed. “I couldn’t quite understand it when she told me that in some places it never snows at all.”

I shivered involuntarily. “My home kingdom of Lanover is one of those. In the south it’s impossibly humid and hot all year round. We have jungles and deserts instead of snow.”

A faraway look entered Oliver’s eyes. “I would like to see it someday.”

“My family would welcome you for a visit anytime, I’m sure.” I smiled at him even as I tried to work out why the image of Oliver in my home unsettled me so much.

Perhaps it was because I was already feeling unsettled, or maybe it was some other instinct, but something made me turn around and scan the road around us. I felt the invisible presence of eyes on my back.

And, sure enough, I got a quick glimpse of a man watching me, before he turned and started up a steep stairway branching off the road. I frowned. It had only been a moment, but I was sure it had been the same man from the palace the day before. He wore identical nondescript clothing, and his eyes had held the same curiosity.

My skin prickled. Of course, it wasn’t ridiculous to think that a palace servant might have an errand in the city. Or that, in an entire day of wandering, we might cross paths with such a person. But still…something about him irritated me. Where had I seen him before?

“Would you like to see the tunnels?” Oliver asked, unaware of my inner perturbation.

I pulled my attention back to him. “I would love to.”

He led me back a little way, and into a brightly lit tavern. The owner called a cheery greeting, apparently unsurprised to see the crown prince in her establishment. Oliver waved back but didn’t stop to talk, leading me past the tables and chairs and into a back room.

He opened a perfectly ordinary looking door, revealing a large stone passage. It was nothing like the bright stone corridors of the palace. This one was rough-hewn, the walls made of the gray stone of the mountain. No natural light reached back here, all illumination coming from a series of lanterns hung at regular intervals.

“Everyone who works or resides in the city pays taxes to contribute toward maintaining the tunnels and the lanterns,” said Oliver when he saw my speculative gaze resting on the lights. “There’s a whole team of people whose sole job is to tend to them.”

I nodded and shivered as I imagined what it would be like if the lanterns were allowed to go out. At least dug back into the mountain, the air had a more consistent temperature. It was cold, but not freezing, and there was no wind to pierce through your clothes and into your bones.

Oliver strode confidently down the tunnel, and I followed, watching the people around me with interest. The passage was wide enough to allow the carts I had seen outside to pass through, although the traffic here seemed lighter. Most people must be taking advantage of the opportunity to escape outside.

The further we walked, the more lost I became.

“Do you have a problem with people getting lost back here?” I asked.

The look Oliver gave me was all too knowing, and I raised my chin defiantly. I wasn’t nervous for myself.

We walked past an opening, and he stopped to point out a series of letters and numbers etched into the wall beside it. “These are like a map of sorts. Or directions. Children learn how to interpret them as soon as they learn to read.”

Now that he had pointed them out, I saw that they were everywhere. Every turn, every opening, every branch of the passage had a code against it. And I could see how necessary they must be. The longer we stayed down here, the more everything began to look the same, and I lost any sense of distance or even direction. I could tell that we were slowly moving downward, though, so I assumed Oliver was leading us back toward the palace.

“Do the tunnels extend all the way into the palace?”

Oliver quickly shook his head. “Apparently when the city was first built there was some talk of it, but it was deemed too dangerous. The royals at the time didn’t want direct access from the city to the palace.”

I narrowed my eyes when I saw a slight twitch across his face. “Very sensible. Of course, it would also be sensible to have a bolt-hole of sorts. A small passage known only to the royal family, perhaps. Not one used for general traffic.”

Aha. This time the twitch was slightly more pronounced. I smiled to myself, but when I caught him watching me suspiciously, it grew into something closer to a smirk. He said nothing to confirm my certainty, but he did give me a rueful smile and a slight shake of his head before turning the conversation.

When we passed the next turning, he paused, his eyes flickering to the marked directions.

“I could have sworn…” he muttered to himself before shrugging and turning to lead me down the marked passage.

“Sworn what?” I asked, a feeling of foreboding sweeping over me.

“We’re close enough to the palace now, that I thought I remembered the way. But don’t worry, the markings were clear.” He smiled reassuringly at me. “That’s why we have them. No one has to rely on their memory. It’s easy for it to play tricks on you down here.”

We were still moving downward, so I tried to relax and trust in his words. But still the feeling of unease remained, and I noticed that this passage seemed deserted.

And I hadn’t seen any openings to other tunnels. I stopped.

“Are you sure? With everything going on—”

I never finished the sentence.

A loud rumbling sounded, and a rush of air blew past us, blowing out some of the lanterns. The distant noise of other traffic cut off, and dust billowed around us.

Oliver took off running back in the direction we had come, and I followed close on his heels. We didn’t have to run far before we hit darkness. He didn’t stop, hurtling forward. I followed, heedless of where I was going, until I collided with his back.

He seemed to be braced against something since he held steady, keeping us both from falling. I splayed my hands across his back—heedless of both propriety and my unpredictable powers—and worked my way over his shoulders and then down his outstretched arm.

Until I felt what he was feeling. A solid wall of stone made up of boulders of various shapes and sizes. He hadn’t mentioned anything about cave ins during our travels, and I had seen no sign of any elsewhere.

“I’m guessing this passage isn’t the way to the palace,” I said.