I forced myself to concentrate. I would not pass out.

A dark silhouette now moved toward us. Dr. Thorn stepped into the dim light. He still looked human, but his face was ghoulish. He had perfect white teeth and his brown/blue eyes reflected the light of my sword.

“Thank you for coming out of the gym,” he said. “I hate middle school dances.”

I tried to swing my sword again, but he was just out of reach.

WHIIIISH! A second projectile shot from somewhere behind Dr. Thorn. He didn’t appear to move. It was as if someone invisible were standing behind him, throwing knives.

Next to me, Bianca yelped. The second thorn impaled itself in the stone wall, half an inch from her face.

“All three of you will come with me,” Dr. Thorn said. “Quietly. Obediently. If you make a single noise, if you call out for help or try to fight, I will show you just how accurately I can throw.”

TWO

THE VICE PRINCIPAL GETS A MISSILE LAUNCHER

I didn’t know what kind of monster Dr. Thorn was, but he was fast.

Maybe I could defend myself if I could get my shield activated. All that it would take was a touch of my wristwatch. But defending the di Angelo kids was another matter. I needed help, and there was only one way I could think to get it.

I closed my eyes.

“What are you doing, Jackson?” hissed Dr. Thorn. “Keep moving!”

I opened my eyes and kept shuffling forward. “It’s my shoulder,” I lied, trying to sound miserable, which wasn’t hard. “It burns.”

“Bah! My poison causes pain. It will not kill you. Walk!”

Thorn herded us outside, and I tried to concentrate. I pictured Grover’s face. I focused on my feelings of fear and danger. Last summer, Grover had created an empathy link between us. He’d sent me visions in my dreams to let me know when he was in trouble. As far as I knew, we were still linked, but I’d never tried to contact Grover before. I didn’t even know if it would work while Grover was awake.

Hey, Grover! I thought. Thorn’s kidnapping us! He’s a poisonous spike-throwing maniac! Help!

Thorn marched us into the woods. We took a snowy path dimly lit by old-fashioned lamplights. My shoulder ached. The wind blowing through my ripped clothes was so cold that I felt like a Percysicle.

“There is a clearing ahead,” Thorn said. “We will summon your ride.”

“What ride?” Bianca demanded. “Where are you taking us?”

“Silence, you insufferable girl!”

“Don’t talk to my sister that way!” Nico said. His voice quivered, but I was impressed that he had the guts to say anything at all.

Dr. Thorn made a growling sound that definitely wasn’t human. It made the hairs stand up on the back of my neck, but I forced myself to keep walking and pretend I was being a good little captive. Meanwhile, I projected my thoughts like crazy—anything to get Grover’s attention: Grover! Apples! Tin cans! Get your furry goat behind out here and bring some heavily armed friends!

“Halt,” Thorn said.

The woods had opened up. We’d reached a cliff overlooking the sea. At least, I sensed the sea was down there, hundreds of feet below. I could hear the waves churning and I could smell the cold salty froth. But all I could see was mist and darkness.

Dr. Thorn pushed us toward the edge. I stumbled, and Bianca caught me.

“Thanks,” I murmured.

“What is he?” she whispered. “How do we fight him?”

“I . . . I’m working on it.”

“I’m scared,” Nico mumbled. He was fiddling with something—a little metal toy soldier of some kind.

“Stop talking!” Dr. Thorn said. “Face me!”

We turned.

Thorn’s two-tone eyes glittered hungrily. He pulled something from under his coat. At first I thought it was a switchblade, but it was only a phone. He pressed the side button and said, “The package—it is ready to deliver.”

There was a garbled reply, and I realized Thorn was in walkie-talkie mode. This seemed way too modern and creepy—a monster using a mobile phone.

I glanced behind me, wondering how far the drop was.

Dr. Thorn laughed. “By all means, Son of Poseidon. Jump! There is the sea. Save yourself.”

“What did he call you?” Bianca muttered.

“I’ll explain later,” I said.

“You do have a plan, right?”

Grover! I thought desperately. Come to me!

Maybe I could get both the di Angelos to jump with me into the ocean. If we survived the fall, I could use the water to protect us. I’d done things like that before. If my dad was in a good mood, and listening, he might help. Maybe.

“I would kill you before you ever reached the water,” Dr. Thorn said, as if reading my thoughts. “You do not realize who I am, do you?”

A flicker of movement behind him, and another missile whistled so close to me that it nicked my ear. Something had sprung up behind Dr. Thorn—like a catapult, but more flexible . . . almost like a tail.

“Unfortunately,” Thorn said, “you are wanted alive, if possible. Otherwise you would already be dead.”

“Who wants us?” Bianca demanded. “Because if you think you’ll get a ransom, you’re wrong. We don’t have any family. Nico and I . . .” Her voice broke a little. “We’ve got no one but each other.”

“Aww,” Dr. Thorn said. “Do not worry, little brats. You will be meeting my employer soon enough. Then you will have a brand-new family.”

“Luke,” I said. “You work for Luke.”

Dr. Thorn’s mouth twisted with distaste when I said the name of my old enemy—a former friend who’d tried to kill me several times. “You have no idea what is happening, Perseus Jackson. I will let the General enlighten you. You are going to do him a great service tonight. He is looking forward to meeting you.”

“The General?” I asked. Then I realized I’d said it with a French accent. “I mean . . . who’s the General?”

Thorn looked toward the horizon. “Ah, here we are. Your transportation.”

I turned and saw a light in the distance, a searchlight over the sea. Then I heard the chopping of helicopter blades getting louder and closer.

“Where are you taking us?” Nico said.

“You should be honored, my boy. You will have the opportunity to join a great army! Just like that silly game you play with cards and dolls.”

“They’re not dolls! They’re figurines! And you can take your great army and—”

“Now, now,” Dr. Thorn warned. “You will change your mind about joining us, my boy. And if you do not, well . . . there are other uses for half-bloods. We have many monstrous mouths to feed. The Great Stirring is underway.”

“The Great what?” I asked. Anything to keep him talking while I tried to figure out a plan.

“The stirring of monsters.” Dr. Thorn smiled evilly. “The worst of them, the most powerful, are now waking. Monsters that have not been seen in thousands of years. They will cause death and destruction the likes of which mortals have never known. And soon we shall have the most important monster of all—the one that shall bring about the downfall of Olympus!”

“Okay,” Bianca whispered to me. “He’s completely nuts.”

“We have to jump off the cliff,” I told her quietly. “Into the sea.”

“Oh, super idea. You’re completely nuts, too.”

I never got the chance to argue with her, because just then an invisible force slammed into me.

Looking back on it, Annabeth’s move was brilliant. Wearing her cap of invisibility, she plowed into the di Angelos and me, knocking us to the ground. For a split second, Dr. Thorn was taken by surprise, so his first volley of missiles zipped harmlessly over our heads. This gave Thalia and Grover a chance to advance from behind—Thalia wielding her magic shield, Aegis.

If you’ve never seen Thalia run into battle, you have never been truly frightened. She uses a huge spear that expands from this collapsible Mace canister she carries in her pocket, but that’s not the scary part. Her shield is modeled after one her dad Zeus uses—also called Aegis—a gift from Athena. The shield has the head of the gorgon Medusa molded into the bronze, and even though it won’t turn you to stone, it’s so horrible, most people will panic and run at the sight of it.