“You’ve done enough already,” I said. “I’ll be fine. And thanks a ton.”

A ton of hay, maybe, Blackjack mused. That sounds good. All right, but be careful, boss. I got a feeling they didn’t come here to meet anything friendly and handsome like me.

I promised to be careful. Then Blackjack took off, circling twice around the monument before disappearing into the clouds.

I looked over at the white van. Everybody was getting out. Grover pointed toward one of the big buildings lining the Mall. Thalia nodded, and the four of them trudged off into the cold wind.

I started to follow. But then I froze.

A block away, the door of a black sedan opened. A man with gray hair and a military buzz cut got out. He was wearing dark shades and a black overcoat. Now, maybe in Washington, you’d expected guys like that to be everywhere. But it dawned on me that I’d seen this same car a couple of times on the highway, going south. It had been following the van.

The guy took out his mobile phone and said something into it. Then he looked around, like he was making sure the coast was clear, and started walking down the Mall in the direction of my friends.

The worst of it was: when he turned toward me, I recognized his face. It was Dr. Thorn, the manticore from Westover Hall.

Invisibility cap on, I followed Thorn from a distance. My heart was pounding. If he had survived that fall from the cliff, then Annabeth must have too. My dreams had been right. She was alive and being held prisoner.

Thorn kept well back from my friends, careful not to be seen.

Finally, Grover stopped in front of a big building that said NATIONAL AIR AND SPACE MUSEUM. The Smithsonian! I’d been here a million years ago with my mom, but everything had looked so much bigger then.

Thalia checked the door. It was open, but there weren’t many people going in. Too cold, and school was out of session. They slipped inside.

Dr. Thorn hesitated. I wasn’t sure why, but he didn’t go into the museum. He turned and headed across the Mall. I made a split-second decision and followed him.

Thorn crossed the street and climbed the steps of the Museum of Natural History. There was a big sign on the door. At first I thought it said CLOSED FOR PIRATE EVENT. Then I realized PIRATE must be PRIVATE.

I followed Dr. Thorn inside, through a huge chamber full of mastodons and dinosaur skeletons. There were voices up ahead, coming from behind a set of closed doors. Two guards stood outside. They opened the doors for Thorn, and I had to sprint to get inside before they closed them again.

Inside, what I saw was so terrible I almost gasped out loud, which probably would’ve gotten me killed.

I was in a huge round room with a balcony ringing the second level. At least a dozen mortal guards stood on the balcony, plus two monsters—reptilian women with double-snake trunks instead of legs. I’d seen them before. Annabeth had called them Scythian dracaenae.

But that wasn’t the worse of it. Standing between the snake women—I could swear he was looking straight down at me—was my old enemy Luke. He looked terrible. His skin was pale and his blond hair looked almost gray, as if he’d aged ten years in just a few months. The angry light in his eyes was still there, and so was the scar down the side of his face, where a dragon had once scratched him. But the scar was now ugly red, as though it had recently been reopened.

Next to him, sitting down so that the shadows covered him, was another man. All I could see were his knuckles on the gilded arms of his chair, like a throne.

“Well?” asked the man in the chair. His voice was just like the one I’d heard in my dream—not as creepy as Kronos’s, but deeper and stronger, like the earth itself was talking. It filled the whole room even though he wasn’t yelling.

Dr. Thorn took off his shades. His two-colored eyes, brown and blue, glittered with excitement. He made a stiff bow, then spoke in his weird French accent: “They are here, General.”

“I know that, you fool,” boomed the man. “But where?”

“In the rocket museum.”

“The Air and Space Museum,” Luke corrected irritably.

Dr. Thorn glared at Luke. “As you say, sir.”

I got the feeling Thorn would just as soon impale Luke with one of his spikes as call him sir.

“How many?” Luke asked.

Thorn pretended not to hear.

“How many?” the General demanded.

“Four, General,” Thorn said. “The satyr, Grover Underwood. And the girl with the spiky black hair and the—how do you say—punk clothes and the horrible shield.”

“Thalia,” Luke said.

“And two other girls—Hunters. One wears a silver circlet.”

“That one I know,” the General growled.

Everyone in the room shifted uncomfortably.

“Let me take them,” Luke said to the General. “We have more than enough—”

“Patience,” the General said. “They’ll have their hands full already. I’ve sent a little playmate to keep them occupied.”

“But—”

“We cannot risk you, my boy.”

“Yes, boy,” Dr. Thorn said with a cruel smile. “You are much too fragile to risk. Let me finish them off.”

“No.” The General rose from his chair, and I got my first look at him.

He was tall and muscular, with light brown skin and slicked-back dark hair. He wore an expensive brown silk suit like the guys on Wall Street wear, but you’d never mistake this dude for a broker. He had a brutal face, huge shoulders, and hands that could snap a flagpole in half. His eyes were like stone. I felt as if I were looking at a living statue. It was amazing he could even move.

“You have already failed me, Thorn,” he said.

“But, General—”

“No excuses!”

Thorn flinched. I’d thought Thorn was scary when I first saw him in his black uniform at the military academy. But now, standing before the General, Thorn looked like a silly wannabe soldier. The General was the real deal. He didn’t need a uniform. He was a born commander.

“I should throw you into the pits of Tartarus for your incompetence,” the General said. “I send you to capture a child of the three elder gods, and you bring me a scrawny daughter of Athena.”

“But you promised me revenge!” Thorn protested. “A command of my own!”

“I am Lord Kronos’s senior commander,” the General said. “And I will choose lieutenants who get me results! It was only thanks to Luke that we salvaged our plan at all. Now get out of my sight, Thorn, until I find some other menial task for you.”

Thorn’s face turned purple with rage. I thought he was going to start frothing at the mouth or shooting spines, but he just bowed awkwardly and left the room.

“Now, my boy.” The General turned to Luke. “The first thing we must do is isolate the half-blood Thalia. The monster we seek will then come to her.”

“The Hunters will be difficult to dispose of,” Luke said. “Zoë Nightshade—”

“Do not speak her name!”

Luke swallowed. “S–sorry, General. I just—”

The General silenced him with a wave of his hand. “Let me show you, my boy, how we will bring the Hunters down.”

He pointed to a guard on the ground level. “Do you have the teeth?”

The guy stumbled forward with a ceramic pot. “Yes, General!”

“Plant them,” he said.

In the center of the room was a big circle of dirt, where I guess a dinosaur exhibit was supposed to go. I watched nervously as the guard took sharp white teeth out of the pot and pushed them into the soil. He smoothed them over while the General smiled coldly.

The guard stepped back from the dirt and wiped his hands. “Ready, General!”

“Excellent! Water them, and we will let them scent their prey.”

The guard picked up a little tin watering can with daisies painted on it, which was kind of bizarre, because what he poured out wasn’t water. It was dark red liquid, and I got the feeling it wasn’t Hawaiian Punch.