Choices I had to make.

The tunnel to the left looked more like a meadow than a tunnel. As it widened, there were weeping wil ows hanging over a dusty footpath, framed by tangles of wildflowers and tal grass. Rol ing hil s spread out under a cloudless blue sky.

You could almost imagine the birds chirping and see the rabbits nibbling grass, if it wasn't a Caster tunnel, where nothing was ever as it seemed.

The tunnel to the right wasn't a tunnel at al but a curving city street underneath its own Caster sky. The dark street was a sharp contrast to the sunny countryside scene of the first tunnel. Liv was scribbling notes in her book. I looked over her shoulder. Asynchronous time zones in adjacent tunnels.

The only light came from a blinking motel sign at the end of the street. Tal apartment buildings with smal iron balconies and fire escape ladders lined either side. Long wires crisscrossed the street from building to building, forming an intricate web with a few pieces of clothing caught in it. An abandoned trol ey track was embedded in the asphalt.

"Which way do we go?" Link was anxious. Wandering around creepy Caster Tunnels wasn't agreeing with him. "I vote for the Wizard of Oz path." He headed for the sunshine.

"I don't think we'l need to vote." I took the Arclight out of my pocket, its heat warming my hand before I noticed the light. Its ebony surface began to glow a pale green.

Liv's eyes were wide. "Amazing."

I took a few steps down the dark street, and the light intensified.

Link came up behind us. "Hel o? I was walkin' away over there? You're not gonna stop me?"

"Watch this." I held the Arclight high enough for him to see and kept walking.

"Kil er flashlight."

Liv checked her selenometer. "You were right. It's guiding us like a compass. My readings confirm it. The moon's magnetic pul is stronger in this direction, which is completely wrong for this time of year."

Link shook his head. "I should've known we'd have to go down the creepy street. We're probably gonna get kil ed by another one a those Vexes."

Every time I took a step closer to the street, the Arclight glowed a brighter and deeper shade of green. "We're going this way."

"Of course we are."

After Link convinced himself we were headed for certain death, the dark street was nothing but a dark street. The short walk to where the motel sign was stil blinking was uneventful. The street was a dead end, leading right up to a doorway under the sign. There was another street running perpendicular to it, lined with unlit doorways. Between the motel sign and the building next to it, there was a steep set of stone stairs. Another Doorwel .

"Should we go left or right?" Liv asked, stepping back onto the street.

I looked at the Arclight's incandescent light, now emerald green. "Neither. We're going up."

I pushed open the heavy door at the top of the stairs. We stepped out from behind an enormous stone arch, stumbling into sunlight that reached through the branches of a gargantuan oak. A woman with white shorts and white hair pedaled a white bike with a white poodle riding in her white bike basket. A giant golden retriever chased the bike. The dog was pul ing a man holding its leash. Lucil e took one look at the retriever and took off into the bushes.

"Lucil e!" I bent down between the bushes, but she was gone. "Great. I lost my aunt's cat again."

"Technical y, she's your cat. She lives with you." Link thrashed around in the azaleas. "Don't worry. She'l come back. Cats have a good sense a direction."

"How would you know that?" Liv looked amused.

"Cat Week. Like Shark Week, but with cats." I shot him a look.

Link turned red. "What? My mom watches a lot a weird stuff on TV."

"Come on."

As we stepped out from behind the trees, a girl with purple hair bumped into Link, almost dropping her giant sketch pad. We were surrounded by dogs and people and bikes and skaters, in a park lined with azalea bushes and shaded by huge oaks. There was an ornate stone fountain in the center, with carved naked mermen spitting water on each other. Walking paths radiated in every direction.

"What happened to the Tunnels? Where are we?" Link was more confused than usual.

"We're in some sort of park," Liv said.

I knew exactly where we were, and I smiled. "Not some park. Forsyth Park. We're in Savannah."

"What?" Liv was digging through her bag.

"Savannah, Georgia. I've been coming here with my mom since I was little."

Liv unfolded a map of what looked like the Caster sky. I recognized the Southern Star, the seven-pointed one that was missing from the real Caster sky. "It doesn't make sense. If the Great Barrier exists, which I'm not saying I believe, it's definitely not in the middle of a Mortal city."

I shrugged. "This is where it led us. What can I say?"

"We walked, like, five miles. How can we be in Savannah?" Link stil hadn't grasped the idea that things were different in the Tunnels.

Liv clicked open her pen, muttering to herself. "Place and time not subject to Mortal physics."

Two little old ladies were pushing two tiny dogs in strol ers. We were definitely in Savannah. Liv closed her red book. "Time, space, distance -- they're al different down here. The Tunnels are part of the Caster world, not the Mortal one."

As if on cue, the glow of the Arclight faded to a glossy black. I slipped it back into my pocket.