His voice broke, and he shrank back to human size. "My son, my greatest pride . . . my poor May . . ."

He sounded so devastated I didn't know what to say. One minute he was ready to vaporize us. Now he looked like he needed a hug.

"Look, Lord Hermes," I said. "I'm sorry, but I need to know. What happened to May? She said something about Luke's fate, and her eyes—"

Hermes glared at me, and my voice faltered. The look on his face wasn't really anger, though. It was pain. Deep, incredible pain.

"I will leave you now," he said tightly. "I have a war to fight."

He began to shine. I turned away and made sure Annabeth did the same, because she was still frozen in shock.

Good luck, Percy, Martha the snake whispered.

Hermes glowed with the light of a supernova. Then he was gone.

Annabeth sat at the foot of her mother's throne and cried. I wanted to comfort her, but I wasn't sure how.

"Annabeth," I said, "it's not your fault. I've never seen Hermes act that way. I guess . . . I don't know . . . he probably feels guilty about Luke. He's looking for somebody to blame. I don't know why he lashed out at you. You didn't do anything to deserve that."

Annabeth wiped her eyes. She stared at the hearth like it was her own funeral pyre.

I shifted uneasily. "Um, you didn't, right?"

She didn't answer. Her Celestial bronze knife was strapped to her arm—the same knife I'd seen in Hestia's vision. All these years, I hadn't realized it was a gift from Luke. I'd asked her many times why she preferred to fight with a knife instead of a sword, and she'd never answered me. Now I knew.

"Percy," she said. "What did you mean about Luke's mother? Did you meet her?"

I nodded reluctantly. "Nico and I visited her. She was a little . . . different." I described May Castellan, and the weird moment when her eyes had started to glow and she talked about her son's fate.

Annabeth frowned. "That doesn't make sense. But why were you visiting—" Her eyes widened. "Hermes said you bear the curse of Achilles. Hestia said the same thing. Did you . . . did you bathe in the River Styx?"

"Don't change the subject."

"Percy! Did you or not?"

"Um . . . maybe a little."

I told her the story about Hades and Nico, and how I'd defeated an army of the dead. I left out the vision of her pulling me out of the river. I still didn't quite understand that part, and just thinking about it made me embarrassed.

She shook her head in disbelief. "Do you have any idea how dangerous that was?"

"I had no choice," I said. "It's the only way I can stand up to Luke."

"You mean . . . di immortales, of course! That's why Luke didn't die. He went to the Styx and . . . Oh no, Luke. What were you thinking?"

"So now you're worried about Luke again," I grumbled.

She stared at me like I'd just dropped from space. "What?"

"Forget it," I muttered. I wondered what Hermes had meant about Annabeth not saving Luke when she'd had the chance. Clearly, she wasn't telling me something. But at the moment I wasn't in the mood to ask. The last thing I wanted to hear about was more of her history with Luke.

"The point is he didn't die in the Styx," I said. "Neither did I. Now I have to face him. We have to defend Olympus."

Annabeth was still studying my face, like she was trying to see differences since my swim in the Styx. "I guess you're right. My mom mentioned—"

"Plan twenty-three."

She rummaged in her pack and pulled out Daedalus's laptop. The blue Delta symbol glowed on the top when she booted it up. She opened a few files and started to read.

"Here it is," she said. "Gods, we have a lot of work to do."

"One of Daedalus's inventions?"

"A lot of inventions . . . dangerous ones. If my mother wants me to use this plan, she must think things are very bad." She looked at me. "What about her message to you: 'Remember the rivers'? What does that mean?"

I shook my head. As usual, I had no clue what the gods were telling me. Which rivers was I supposed to remember? The Styx? The Mississippi?

Just then the Stoll brothers ran in to the throne room.

"You need to see this," Connor said. "Now."

The blue lights in the sky had stopped, so at first I didn't understand what the problem was.

The other campers had gathered in a small park at the edge of the mountain. They were clustered at the guardrail, looking down at Manhattan. The railing was lined with those tourist binoculars, where you could deposit one golden drachma and see the city. Campers were using every single one.

I looked down at the city. I could see almost everything from here—the East River and the Hudson River carving the shape of Manhattan, the grid of streets, the lights of skyscrapers, the dark stretch of Central Park in the north. Everything looked normal, but something was wrong. I felt it in my bones before I realized what it was.

"I don't . . . hear anything," Annabeth said.

That was the problem.

Even from this height, I should've heard the noise of the city—millions of people bustling around, thousands of cars and machines—the hum of a huge metropolis. You don't think about it when you live in New York, but it's always there. Even in the dead of night, New York is never silent.

But it was now.

I felt like my best friend had suddenly dropped dead.

"What did they do?" My voice sounded tight and angry. "What did they do to my city?"

I pushed Michael Yew away from the binoculars and took a look.

In the streets below, traffic had stopped. Pedestrians were lying on the sidewalks, or curled up in doorways. There was no sign of violence, no wrecks, nothing like that. It was as if all the people in New York had simply decided to stop whatever they were doing and pass out.

"Are they dead?" Silena asked in astonishment.

Ice coated my stomach. A line from the prophecy rang in my ears: And see the world in endless sleep. I remembered Grover's story about meeting the god Morpheus in Central Park. You're lucky I'm saving my energy for the main event.

"Not dead," I said. "Morpheus has put the entire island of Manhattan to sleep. The invasion has started."

Mrs. O'Leary was the only one happy about the sleeping city.

We found her pigging out at an overturned hot dog stand while the owner was curled up on the sidewalk, sucking his thumb.

Argus was waiting for us with his hundred eyes wide open. He didn't say anything. He never does. I guess that's because he supposedly has an eyeball on his tongue. But his face made it clear he was freaking out.

I told him what we'd learned in Olympus, and how the gods would not be riding to the rescue. Argus rolled his eyes in disgust, which looked pretty psychedelic since it made his whole body swirl.

"You'd better get back to camp," I told him. "Guard it as best you can."

He pointed at me and raised his eyebrow quizzically.

"I'm staying," I said.

Argus nodded, like this answer satisfied him. He looked at Annabeth and drew a circle in the air with his finger.

"Yes," Annabeth agreed. "I think it's time."

"For what?" I asked.

Argus rummaged around in the back of his van. He brought out a bronze shield and passed it to Annabeth. It looked pretty much standard issue—the same kind of round shield we always used in capture the flag. But when Annabeth set it on the ground, the reflection on the polished metal changed from sky and buildings to the Statue of Liberty—which wasn't anywhere close to us.

"Whoa," I said. "A video shield."

"One of Daedalus's ideas," Annabeth said. "I had Beckendorf make this before—" She glanced at Silena. "Um, anyway, the shield bends sunlight or moonlight from anywhere in the world to create a reflection. You can literally see any target under the sun or moon, as long as natural light is touching it. Look."