Bianca was silent. "You should tell Thalia the rest of your dream."

"No. It would not help."

"But if your suspicions are correct, about the General—"

"I have thy word not to talk about that," Zoe said. She sounded really anguished. "We will find out soon enough. Now come. Dawn is breaking."

Nico scooted out of their way. He was faster than me.

As the girls sprinted down the steps, Zoe almost ran into me. She froze, her eyes narrowing. Her hand crept toward her bow, but then Bianca said, "The lights of the Big House are on. Hurry!"

And Zoe followed her out of the pavilion.

I could tell what Nico was thinking. He took a deep breath and was about to run after his sister when I took off the invisibility cap and said, "Wait."

He almost slipped on the icy steps as he spun around to find me. "Where did you come from?"

"I've been here the whole time. Invisible."

He mouthed the word invisible. "Wow. Cool."

"How did you know Zoe and your sister were here?"

He blushed. "I heard them walk by the Hermes cabin. I don't… I don't sleep too well at camp. So I heard footsteps, and them whispering. And so I kind of followed."

"And now you're thinking about following them on the quest," I guessed.

"How did you know that?"

"Because if it was my sister, I'd probably be thinking the same thing. But you can't."

He looked defiant. "Because I'm too young?"

"Because they won't let you. They'll catch you and send you back here. And… yeah, because you're too young. You remember the manticore? There will be lots more like that. More dangerous. Some of the heroes will die."

He shoulders sagged. He shifted from foot to foot. "Maybe you're right. But, but you can go for me."

"Say what?"

"You can turn invisible. You can go!"

"The Hunters don't like boys," I reminded him. "If they find out—"

"Don't let them find out. Follow them invisibly. Keep an eye on my sister! You have to. Please?"

"Nico—"

"You're planning to go anyway, aren't you?"

I wanted to say no. But he looked me in the eyes, and I somehow couldn't lie to him.

"Yeah," I said. "I have to find Annabeth. I have to help, even if they don't want me to."

"I won't tell on you," he said. "But you have to promise to keep my sister safe."

"I… that's a big thing to promise, Nico, on a trip like this. Besides, she's got Zoe, Grover, and Thalia—"

"Promise," he insisted.

"I'll do my best. I promise that."

"Get going, then!" he said. "Good luck!"

It was crazy. I wasn't packed. I had nothing but the cap and the sword and the clothes I was wearing. I was supposed to be going home to Manhattan this morning. "Tell Chiron—"

"I'll make something up." Nico smiled crookedly. "I'm good at that. Go on!"

I ran, putting on Annabeth's cap. As the sun came up, I turned invisible. I hit the top of Half-Blood Hill in time to see the camp's van disappearing down the farm road, probably Argus taking the quest group into the city. After that they would be on their own.

I felt a twinge of guilt, and stupidity, too. How was I supposed to keep up with them. Run?

Then I heard the beating of huge wings. Blackjack landed next to me. He began casually nuzzling a few tufts of grass that stuck through the ice.

If I was guessing, boss, I'd say you need a getaway horse. You interested?

A lump of gratitude stuck in my throat, but I managed to say, "Yeah. Let's fly."

NINE

I LEARN HOW TO GROW ZOMBIES

The thing about flying on a pegasus during the daytime is that if you're not careful, you can cause a serious traffic accident on the Long Island Expressway. I had to keep Blackjack up in the clouds, which were, fortunately, pretty low in the winter. We darted around, trying to keep the white Camp Half-Blood van in sight. And if it was cold on the ground, it was seriously cold in the air, with icy rain stinging my skin.

I was wishing I'd brought some of that Camp Half-Blood orange thermal underwear they sold in the camp store, but after the story about Phoebe and the centaur-blood T-shirt, I wasn't sure I trusted their products anymore.

We lost the van twice, but I had a pretty good sense that they would go into Manhattan first, so it wasn't too difficult to pick up their trail again.

Traffic was bad with the holidays and all. It was mid morning before they got into the city. I landed Blackjack near the top of the Chrysler Building and watched the white camp van, thinking it would pull into the bus station, but it just kept driving.

"Where's Argus taking them?" I muttered.

Oh, Argus ain't driving, boss, Blackjack told me. That girl is.

"Which girl?"

The Hunter girl. With the silver crown thing in her hair.

"Zoe?"

That's the one. Hey, look! There's a donut shop. Can we get something to go?

I tried explaining to Blackjack that taking a flying horse to a donut shop would give every cop in there a heart attack, but he didn't seem to get it. Meanwhile, the van kept snaking its way toward the Lincoln Tunnel. It had never even occurred to me that Zoe could drive. I mean, she didn't look sixteen. Then again, she was immortal. I wondered if she had a New York license, and if so, what her birth date said.

"Well," I said. "Lets get after them."

We were about to leap off the Chrysler Building when Blackjack whinnied in alarm and almost threw me. Something was curling around my leg like a snake. I reached for my sword, but when I looked down, there was no snake. Vines—grape vines—had sprouted from the cracks between the stones of the building. They were wrapping around Blackjack's legs, lashing down my ankles so we couldn't move.

"Going somewhere?" Mr. D asked.

He was leaning against the building with his feet levitating in the air, his leopard-skin warm-up suit and black hair whipping around in the wind.

God alert! Blackjack yelled. It's the wine dude!

Mr. D sighed in exasperation. "The next person, or horse, who calls me the 'wine dude' will end up in a bottle of Merlot!"

"Mr. D." I tried to keep my voice calm as the grape vines continued to wrap around my legs. "What do you want?"

"Oh, what do I want? You thought, perhaps, that the immortal, all-powerful director of camp would not notice you leaving without permission?"

"Well… maybe."

"I should throw you off this building, minus the flying horse, and see how heroic you sound on the way down."

I balled my fists. I knew I should keep my mouth shut, but Mr. D was about to kill me or haul me back to camp in shame, and I couldn't stand either idea. "Why do you hate me so much? What did I ever do to you?"

Purple flames flickered in his eyes. "You're a hero, boy. I need no other reason."

"I have to go on this quest! I've got to help my friends. That's something you wouldn't understand!"

Um, boss, Blackjack said nervously. Seeing as how we're wrapped in vines nine hundred feet in the air, you might want to talk nice.

The grape vines coiled tighter around me. Below us, the white van was getting farther and farther away. Soon it would be out of sight.

"Did I ever tell you about Ariadne?" Mr. D asked. "Beautiful young princess of Crete? She liked helping her friends, too. In fact, she helped a young hero named Theseus, also a son of Poseidon. She gave him a ball of magical yarn that let him find his way out of the Labyrinth.

And do you know how Theseus rewarded her?"

The answer I wanted to give was I don't care! But I didn't figure that would make Mr. D finish his story any faster.

"They got married," I said. "Happily ever after. The end."

Mr. D sneered. "Not quite. Theseus said he would marry her. He took her aboard his ship and sailed for Athens. Halfway back, on a little island called Naxos, he… What's the word you mortals use today?… he dumped her. I found her there, you know. Alone. Heartbroken. Crying her eyes out. She had given up everything, left everything she knew behind, to help a dashing young hero who tossed her away like a broken sandal."

"That's wrong," I said. "But that was thousands of years ago. What's that got to do with me?"

Mr. D regarded me coldly. "I fell in love with Ariadne, boy. I healed her broken heart. And when she died, I made her my immortal wife on Olympus. She waits for me even now. I shall go back to her when I am done with this infernal century of punishment at your ridiculous camp."

I stared at him. "You're… you're married? But I thought you got in trouble for chasing a wood nymph—"

"My point is you heroes never change. You accuse us gods of being vain. You should look at yourselves. You take what you want, use whoever you have to, and then you betray everyone around you. So you'll excuse me if I have no love for heroes. They are a selfish, ungrateful lot. Ask Ariadne. Or Medea. For that matter, ask Zoe Nightshade."

"What do you mean, ask Zoe?"

He waved his hand dismissively. "Go. Follow your silly friends."

The vines uncurled around my legs.

I blinked in disbelief. "You're… you're letting me go? Just like that?"

"The prophecy says at least two of you will die. Perhaps I'll get lucky and you'll be one of them. But mark my words, Son of Poseidon, live or die, you will prove no better than the other heroes."

With that, Dionysus snapped his fingers. His image folded up like a paper display. There was a pop and he was gone, leaving a faint scent of grapes that was quickly blown away by the wind.

Too close, Blackjack said.

I nodded, though I almost would have been less worried if Mr. D had hauled me back to camp. The fact that he'd let me go meant he really believed we stood a fair chance of crashing and burning on this quest.

"Come on, Blackjack," I said, trying to sound upbeat. "I'll buy you some donuts in New Jersey."

As it turned out, I didn't buy Blackjack donuts in New Jersey. Zoe drove south like a crazy person, and we were into Maryland before she finally pulled over at a rest stop. Blackjack darn near tumbled out of the sky, he was so tired.

I'll be okay, boss, he panted. Just… just catching my breath.

"Stay here," I told him. "I'm going to scout."

'Stay here' I can handle. I can do that.

I put on my cap of invisibility and walked over to the convenience store. It was difficult not to sneak. I had to keep reminding myself that nobody could see me. It was hard, too, because I had to remember to get out of people's way so they wouldn't slam into me.

I thought I'd go inside and warm up, maybe get a cup of hot chocolate or something. I had a little change in my pocket. I could leave it on the counter. I was wondering if the cup would turn invisible when I picked it up, or if I'd have to deal with a floating hot chocolate problem, when my whole plan was ruined by Zoe, Thalia, Bianca, and Grover all coming out of the store.

"Grover, are you sure?" Thalia was saying.

"Well… pretty sure. Ninety-nine percent. Okay, eighty-five percent."

"And you did this with acorns?" Bianca asked, like she couldn't believe it.