The Battle of the Labyrinth

king’s palace in Crete anymore,” I guessed. “The Labyrinth is under some building in America.”
    See? It only took me a few years to figure things out. I knew that important places moved around with Western Civilization, like Mount Olympus being over the Empire State Building, and the Underworld entrance being in Los Angeles. I was feeling pretty proud of myself.
    Annabeth rolled her eyes. “Under a building? Please, Percy. The Labyrinth is huge . It wouldn’t fit under a single city, much less a single building.”
    I thought about my dream of Nico at the River Styx. “So . . . is the Labyrinth part of the Underworld?”
    “No.” Annabeth frowned. “Well, there may be passages from the Labyrinth down into the Underworld. I’m not sure. But the Underworld is way, way down. The Labyrinth is right under the surface of the mortal world, kind of like a second skin. It’s been growing for thousands of years, lacing its way under Western cities, connecting everything together underground. You can get anywhere through the Labyrinth.”
    “If you don’t get lost,” Grover muttered. “And die a horrible death.”
    “Grover, there has to be a way,” Annabeth said. I got the feeling they’d had this conversation before. “Clarisse lived.”
    “Barely!” Grover said. “And the other guy—”
    “He was driven insane. He didn’t die.”
    “Oh, joy.” Grover’s lower lip quivered. “That makes me feel much better.”
    “Whoa,” I said. “Back up. What’s this about Clarisse and a crazy guy?”
    Annabeth glanced over toward the Ares table. Clarisse was watching us like she knew what we were talking about, but then she fixed her eyes on her breakfast plate.
    “Last year,” Annabeth said, lowering her voice, “Clarisse went on a mission for Chiron.”
    “I remember,” I said. “It was secret.”
    Annabeth nodded. Despite how serious she was acting, I was happy she wasn’t mad at me anymore. And I kind of liked the fact that she’d broken the rules to come sit next to me.
    “It was secret,” Annabeth agreed, “because she found Chris Rodriguez.”
    “The guy from the Hermes cabin?” I remembered him from two years ago. We’d eavesdropped on Chris Rodriguez aboard Luke’s ship, the Princess Andromeda . Chris was one of the half-bloods who’d abandoned camp and joined the Titan army.
    “Yeah,” Annabeth said. “Last summer he just appeared in Phoenix, Arizona, near Clarisse’s mom’s house.”
    “What do you mean he just appeared?”
    “He was wandering around the desert, in a hundred and twenty degrees, in full Greek armor, babbling about string.”
    “String,” I said.
    “He’d been driven completely insane. Clarisse brought him back to her mom’s house so the mortals wouldn’t institutionalize him. She tried to nurse him back to health. Chiron came out and interviewed him, but it wasn’t much good. The only thing they got out of him: Luke’s men have been exploring the Labyrinth.”
    I shivered, though I wasn’t sure exactly why. Poor Chris . . . he hadn’t been that bad a guy. What could’ve driven him mad? I looked at Grover, who was chewing up the rest of his fork.
    “Okay,” I asked. “Why were they exploring the Labyrinth?”
    “We weren’t sure,” Annabeth said. “That’s why Clarisse went on a scouting expedition. Chiron kept things hushed up because he didn’t want anyone panicking. He got me involved because . . . well, the Labyrinth has always been one of my favorite subjects. The architecture involved—” Her expression turned a little dreamy. “The builder, Daedalus, was a genius. But the point is, the Labyrinth has entrances everywhere. If Luke could figure out how to navigate it, he could move his army around with incredible speed.”
    “Except it’s a maze, right?”
    “Full of horrible traps,” Grover agreed. “Dead ends. Illusions. Psychotic goat-killing monsters.”
    “But not if you had Ariadne’s string,” Annabeth said.
    “In the old days, Ariadne’s string guided Theseus out of the maze. It was a navigation instrument of some kind, invented by Daedalus. And Chris Rodriguez was mumbling about string.”
    “So Luke is trying to find Ariadne’s string,” I said. “Why? What’s he planning?”
    Annabeth shook her head. “I don’t know. I thought maybe he wanted to invade camp through the maze, but that doesn’t make any sense. The closest entrances Clarisse found were in Manhattan, which wouldn’t help Luke get past