I rubbed my eyes, surprised to be walking behind Liv instead of lying on the ground. It was crazy to think I could be watching Lena in one place and following Liv through the Tunnels at the same time. How was it possible?

The strange visions, with the off-kilter perspective and the flashing images -- what was happening? Why was I able to see Lena and John? I had to figure it out.

I looked down at my hands. I wasn't holding anything except the Arclight. I tried to think back to the first time I saw Lena this way. It was in my bathroom, and I didn't have the Arclight then. The only thing I'd been touching was the sink. There had to be a common thread, but I couldn't see it.

Ahead, the tunnel opened up into a stone hall, where the entrances to four tunnels converged.

Link sighed. "Which way?"

I didn't answer. Because when I looked down at the Arclight, I saw something else just beyond it.

Lucille.

Sitting in the mouth of the tunnel opposite us, expectantly. I reached into my back pocket and pulled out the silver tag Aunt Prue had given me, with Lucille's name engraved on it. I could still hear Aunt Prue's voice.

See you still got that cat. I was just waitin' for the right time ta let her offa that clothesline. She knows a trick or two. You'll see.

In a split second, everything fell into place and I knew.

It was Lucille.

The images speeding past me every time I found my way to Lena and John. The ground so close, closer than it could ever be if I was standing. The strange vantage point, as if I was lying on my stomach looking up at them. It all made sense. The way Lucille kept disappearing and reappearing randomly. Only it wasn't random.

I tried to remember the times Lucille had vanished, ticking them off in my head one by one. The first time I saw Lena with John and Ridley, I was staring into my bathroom mirror. I didn't remember Lucille disappearing, but I remembered she was sitting on the front porch the next morning. Which didn't make any sense, because we never left her outside at night.

The second time, Lucille had bolted in Forsyth Park when we got to Savannah, and she didn't show up until after we left Bonaventure -- after I had seen Lena and John when I was at Aunt Caroline's. And this time, Link noticed Lucille was gone when we came back down into the Tunnels, but now here she was, sitting in front of us, right after I had just seen Lena.

I wasn't the one seeing Lena.

Lucille was. She was tracking Lena, the same way we were following the maps or the lights or the pull of the moon. I was watching Lena through the cat's eyes, maybe the same way Macon had watched the world through Boo's. How was it possible? Lucille wasn't a Caster cat any more than I was a Caster.

Was she?

"What are you, Lucille?"

The cat looked me in the eye and cocked her head to the side.

"Ethan?" Liv was watching me. "Are you all right?"

"Yeah." I shot Lucille a meaningful look. She ignored me, sniffing the tip of her tail gracefully.

"You realize she's a cat." Liv was still staring at me curiously.

"I know."

"Just checking."

Great. Not only was I talking to a cat, but now I was talking about talking to a cat. "We should get going."

Liv took a deep breath. "Yes, about that. I'm afraid we can't."

"Why not?"

Liv motioned me over to where all of Aunt Prue's maps were laid out on the smooth dirt. "You see this mark here? That's the nearest Doorwell. It took me a while, but I've figured out loads of things about this map. Your aunt wasn't kidding. She must have spent years marking it up."

"The Doorwells are marked?"

"Looks that way on the map. See these red D's, with the little circles around them?" They were everywhere. "And these thin red lines? I believe they're closer to the surface. There's a pattern. It seems the darker the color gets, the deeper underground."

I pointed to a grid of black lines. "You're saying these would be the deepest."

Liv nodded. "Possibly also the Darkest. The concept of Dark and Light territories within the Underground -- it's groundbreaking, really. Certainly not widely known."

"So what's the problem?"

"This." She pointed to two words scribbled across the southernmost edge of the largest page. L O C A S I L E N T I A .

I remembered the second word. It sounded like the one Lena said when she laid the Cast to keep me from telling her family she was leaving Gatlin. "You're saying the map is too quiet?"

Liv shook her head. "This is where the map falls silent, I'm afraid. Because we're at the end. We've reached the southern shore, which means we're off the map. Terra incognita." She shrugged. "You know what they say. Hic dracones sunt."

"Yeah, I hear that one a lot." I had no idea what she was talking about.

"'Here be dragons.' It's what sailors used to write on maps five hundred years ago, when the map ended but the ocean didn't."

"I'd rather face dragons than Sarafine." I looked at the place where Liv was tapping her finger. The web of Tunnels we had come from was as complex as any highway system. "So what now?"

"I'm out of ideas. I've done nothing but stare at this map since your aunt gave it to us, and I still don't know how to get to the Great Barrier. And I don't even know if I believe it's a real place." We stared at the map together. "I'm sorry.