We crowded around as Annabeth concentrated. The image zoomed and spun at first, so I got motion sickness just watching it. We were in the Central Park Zoo, then zooming down East 60th, past Bloomingdale's, then turning on Third Avenue.

"Whoa," Connor Stoll said. "Back up. Zoom in right there."

"What?" Annabeth said nervously. "You see invaders?"

"No, right there—Dylan's Candy Bar." Connor grinned at his brother. "Dude, it's open. And everyone is asleep. Are you thinking what I'm thinking?"

"Connor!" Katie Gardner scolded. She sounded like her mother, Demeter. "This is serious. You are not going to loot a candy store in the middle of a war!"

"Sorry," Connor muttered, but he didn't sound very ashamed.

Annabeth passed her hand in front of the shield, and another scene popped up: FDR Drive, looking across the river at Lighthouse Park.

"This will let us see what's going on across the city," she said. "Thank you, Argus. Hopefully we'll see you back at camp . . . someday."

Argus grunted. He gave me a look that clearly meant Good luck; you'll need it, then climbed into his van. He and the two harpy drivers swerved away, weaving around clusters of idle cars that littered the road.

I whistled for Mrs. O'Leary, and she came bounding over.

"Hey, girl," I said. "You remember Grover? The satyr we met in the park?"

"WOOF!"

I hoped that meant Sure I do! And not, Do you have more hot dogs?

"I need you to find him," I said. "Make sure he's still awake. We're going to need his help. You got that? Find Grover!"

Mrs. O'Leary gave me a sloppy wet kiss, which seemed kind of unnecessary. Then she raced off north.

Pollux crouched next to a sleeping policeman. "I don't get it. Why didn't we fall asleep too? Why just the mortals?"

"This is a huge spell," Silena Beauregard said. "The bigger the spell, the easier it is to resist. If you want to sleep millions of mortals, you've got to cast a very thin layer of magic. Sleeping demigods is much harder."

I stared at her. "When did you learn so much about magic?"

Silena blushed. "I don't spend all my time on my wardrobe."

"Percy," Annabeth called. She was still looking at the shield. "You'd better see this."

The bronze image showed Long Island Sound near La Guardia. A fleet of a dozen speedboats raced through the dark water toward Manhattan. Each boat was packed with demigods in full Greek armor. At the back of the lead boat, a purple banner emblazoned with a black scythe flapped m the night wind. I'd never seen that design before, but it wasn't hard to figure out: the battle flag of Kronos.

"Scan the perimeter of the island," I said. "Quick."

Annabeth shifted the scene south to the harbor. A Staten Island Ferry was plowing through the waves near Ellis Island. The deck was crowded with dracaenae and a whole pack of hellhounds. Swimming in front of the ship was a pod of marine mammals. At first I thought they were dolphins. Then I saw their doglike faces and the swords strapped to their waists, and I realized they were telkhines—sea demons.

The scene shifted again: the Jersey shore, right at the entrance to the Lincoln Tunnel. A hundred assorted monsters were marching past the lanes of stopped traffic: giants with clubs, rogue Cyclopes, a few fire-spitting dragons, and just to rub it in, a World War II-era Sherman tank, pushing cars out of its way as it rumbled into the tunnel.

"What's happening with the mortals outside Manhattan?" I said. "Is the whole state asleep?"

Annabeth frowned. "I don't think so, but it's strange. As far as I can tell from these pictures, Manhattan is totally asleep. Then there's like a fifty-mile radius around the island where time is running really, really slow. The closer you get to Manhattan, the slower it is."

She showed me another scene—a New Jersey highway. It was Saturday evening, so the traffic wasn't as bad as it might've been on a weekday. The drivers looked awake, but the cars were moving at about one mile per hour. Birds flew overhead in slow motion.

"Kronos," I said. "He's slowing time."

"Hecate might be helping," Katie Gardner said. "Look how the cars are all veering away from the Manhattan exits, like they're getting a subconscious message to turn back."

"I don't know." Annabeth sounded really frustrated. She hated not knowing. "But somehow they've surrounded Manhattan in layers of magic. The outside world might not even realize something is wrong. Any mortals coming toward Manhattan will slow down so much they won't know what's happening."

"Like flies in amber," Jake Mason murmured.

Annabeth nodded. "We shouldn't expect any help coming in."

I turned to my friends. They looked stunned and scared, and I couldn't blame them. The shield had shown us at least three hundred enemies on the way. There were forty of us. And we were alone.

"All right," I said. "We're going to hold Manhattan."

Silena tugged at her armor. "Um, Percy, Manhattan is huge."

"We are going to hold it," I said. "We have to."

"He's right," Annabeth said. "The gods of the wind should keep Kronos's forces away from Olympus by air, so he'll try a ground assault. We have to cut off the entrances to the island."

"They have boats," Michael Yew pointed out.

An electric tingle went down my back. Suddenly I understood Athena's advice: Remember the rivers.

"I'll take care of the boats," I said.

Michael frowned. "How?"

"Just leave it to me," I said. "We need to guard the bridges and tunnels. Let's assume they'll try a midtown or downtown assault, at least on their first try. That would be the most direct way to the Empire State Building. Michael, take Apollo's cabin to the Williamsburg Bridge. Katie, Demeter's cabin takes the Brooklyn-Battery Tunnel. Grow thorn bushes and poison ivy in the tunnel. Do whatever you have to do, but keep them out of there! Conner, take half of Hermes cabin and cover the Manhattan Bridge. Travis, you take the other half and cover the Brooklyn Bridge. And no stopping for looting or pillaging!"

"Awwww!" the whole Hermes cabin complained.

"Silena, take the Aphrodite crew to the Queens-Midtown Tunnel."

"Oh my gods," one of her sisters said. "Fifth Avenue is so on our way! We could accessorize, and monsters, like, totally hate the smell of Givenchy."

"No delays," I said. "Well . . . the perfume thing, if you think it'll work."

Six Aphrodite girls kissed me on the cheek in excitement.

"All right, enough!" I closed my eyes, trying to think of what I'd forgotten. "The Holland Tunnel. Jake, take the Hephaestus cabin there. Use Greek fire, set traps. Whatever you've got."

He grinned. "Gladly. We've got a score to settle. For Beckendorf!"

The whole cabin roared in approval.

"The 59th Street Bridge," I said. "Clarisse—"

I faltered. Clarisse wasn't here. The whole Ares cabin, curse them, was sitting back at camp.

"We'll take that," Annabeth stepped in, saving me from an embarrassing silence. She turned to her siblings. "Malcolm, take the Athena cabin, activate plan twenty-three along the way, just like I showed you. Hold that position."

"You got it."

"I'll go with Percy," she said. "Then we'll join you, or we'll go wherever we're needed."

Somebody in the back of the group said, "No detours, you two."

There were some giggles, but I decided to let it pass.

"All right," I said. "Keep in touch with cell phones."

"We don't have cell phones," Silena protested.

I reached down, picked up some snoring lady's BlackBerry, and tossed it to Silena. "You do now. You all know Annabeth's number, right? If you need us, pick up a random phone and call us. Use it once, drop it, then borrow another one if you have to. That should make it harder for the monsters to zero in on you."