The creature on the left looked disturbingly like a telkhine. His face was wolfish. His body was vaguely like a seal's—sleek black with flipper hands and feet. His eyes glowed radiation green.

The dude on the right was more humanoid. He was dressed in rags and seaweed, with a chain-mail coat made of bottle caps and old plastic six-pack holders. His face was blotchy with algae, and his beard was overgrown. His deep blue eyes burned with anger.

The seal, who had to be the god of the East River, said, "Are you trying to get yourself killed, kid? Or are you just extra stupid?"

The bearded spirit of the Hudson scoffed. "You're the expert on stupid, East."

"Watch it, Hudson," East growled. "Stay on your side of the island and mind your business."

"Or what? You'll throw another garbage barge at me?"

They floated toward each other, ready to fight.

"Hold it!" I yelled. "We've got a bigger problem."

"The kid's right," East snarled. "Let's both kill him, then we'll fight each other."

"Sounds good," Hudson said.

Before I could protest, a thousand scraps of garbage surged off the bottom and flew straight at me from both directions: broken glass, rocks, cans, tires.

I was expecting it, though. The water in front of me thickened into a shield. The debris bounced off harmlessly. Only one piece got through—a big chunk of glass that hit my chest and probably should've killed me, but it shattered against my skin.

The two river gods stared at me.

"Son of Poseidon?" East asked.

I nodded.

"Took a dip in the Styx?" Hudson asked.

"Yep."

They both made disgusted sounds.

"Well, that's perfect," East said. "Now how do we kill him?"

"We could electrocute him," Hudson mused. "If I could just find some jumper cables—"

"Listen to me!" I said. "Kronos's army is invading Manhattan.'"

"Don't you think we know that?" East asked. "I can feel his boats right now. They're almost across."

"Yep," Hudson agreed. "I got some filthy monsters crossing my waters too."

"So stop them," I said. "Drown them. Sink their boats."

"Why should we?" Hudson grumbled. "So they invade Olympus. What do we care?"

"Because I can pay you." I took out the sand dollar my father had given me for my birthday.

The river gods' eyes widened.

"It's mine!" East said. "Give it here, kid, and I promise none of Kronos's scum are getting across the East River."

"Forget that," Hudson said. "That sand dollar's mine, unless you want me to let all those ships cross the Hudson."

"We'll compromise." I broke the sand dollar in half. A ripple of clean fresh water spread out from the break, as if all the pollution in the bay were being dissolved.

"You each get half," I said. "In exchange, you keep all of Kronos's forces away from Manhattan."

"Oh, man," Hudson whimpered, reaching out for the sand dollar. "It's been so long since I was clean."

"The power of Poseidon," East River murmured. "He's a jerk, but he sure knows how to sweep pollution away."

They looked at each other, then spoke as one: "It's a deal."

I gave them each a sand-dollar half, which they held reverently.

"Um, the invaders?" I prompted.

East flicked his hand. "They just got sunk."

Hudson snapped his fingers. "Bunch of hellhounds just took a dive."

"Thank you," I said. "Stay clean."

As I rose toward the surface, East called out, "Hey, kid, any time you got a sand dollar to spend, come on back. Assuming you live."

"Curse of Achilles," Hudson snorted. "They always think that'll save them, don't they?"

"If only he knew," East agreed. They both laughed, dissolving into the water.

Back on the shore, Annabeth was talking on her cell phone, but she hung up as soon as she saw me. She looked pretty shaken.

"It worked," I told her. "The rivers are safe."

"Good," she said. "Because we've got other problems. Michael Yew just called. Another army is marching over the Williamsburg Bridge. The Apollo cabin needs help. And Percy, the monster leading the enemy . . . it's the Minotaur."

ELEVEN

WE BREAK A BRIDGE

Fortunately, Blackjack was on duty.

I did my best taxicab whistle, and within a few minutes two dark shapes circled out of the sky. They looked like hawks at first, but as they descended I could make out the long galloping legs of pegasi.

Yo, boss. Blackjack landed at a trot, his friend Porkpie right behind him. Man, I thought those wind gods were gonna knock us to Pennsylvania until we said we were with you!

"Thanks for coming," I told him. "Hey, why do pegasi gallop as they fly, anyway?"

Blackjack whinnied. Why do humans swing their arms as they walk? I dunno, boss. It just feels right. Where to?

"We need to get to the Williamsburg Bridge," I said.

Blackjack lowered his neck. You're darn right, boss. We flew over it on the way here, and it don't look good. Hop on!

On the way to the bridge, a knot formed in the pit of my stomach. The Minotaur was one of the first monsters I'd ever defeated. Four years ago he'd nearly killed my mother on Half-Blood Hill. I still had nightmares about that.

I'd been hoping he would stay dead for a few centuries, but I should've known my luck wouldn't hold.

We saw the battle before we were close enough to make out individual fighters. It was well after midnight now, but the bridge blazed with light. Cars were burning. Arcs of fire streamed in both directions as flaming arrows and spears sailed through the air.

We came in for a low pass, and I saw the Apollo campers retreating. They would hide behind cars and snipe at the approaching army, setting off explosive arrows and dropping caltrops in the road, building fiery barricades wherever they could, dragging sleeping drivers out of their cars to get them out of harm's way. But the enemy kept advancing. An entire phalanx of dracaenae marched in the lead, their shields locked together, spear tips bristling over the top. An occasional arrow would connect with their snaky trunks, or a neck, or a chink in their armor, and the unlucky snake woman would disintegrate, but most of the Apollo arrows glanced harmlessly off their shield wall. About a hundred more monsters marched behind them.

Hellhounds leaped ahead of the line from time to time. Most were destroyed with arrows, but one got hold of an Apollo camper and dragged him away. I didn't see what happened to him next. I didn't want to know.

"There!" Annabeth called from the back of her pegasus.

Sure enough, in the middle of the invading legion was Old Beefhead himself.

The last time I'd seen the Minotaur, he'd been wearing nothing but his tighty whities. I don't know why. Maybe he'd been shaken out of bed to chase me. This time, he was prepared for battle.

From the waist down, he wore standard Greek battle gear—a kiltlike apron of leather and metal flaps, bronze greaves covering his legs, and tightly wrapped leather sandals. His top was all bull—hair and hide and muscle leading to a head so large he should've toppled over just from the weight of his horns. He seemed larger than the last time I'd seen him—ten feet tall at least. A double-bladed axe was strapped to his back, but he was too impatient to use it. As soon as he saw me circling overhead (or sniffed me, more likely, since his eyesight was bad), he bellowed and picked up a white limousine.

"Blackjack, dive!" I yelled.

What? The pegasus asked. No way could he . . . Holy horse feed!

We were at least a hundred feet up, but the limo came sailing toward us, flipping fender over fender like a two-ton boomerang. Annabeth and Porkpie swerved madly to the left, while Blackjack tucked in his wings and plunged. The limo sailed over my head, missing by maybe two inches. It cleared the suspension lines of the bridge and fell toward the East River.

Monsters jeered and shouted, and the Minotaur picked up another car.

"Drop us behind the lines with the Apollo cabin," I told Blackjack. "Stay in earshot but get out of danger!"

I ain't gonna argue, boss!

Blackjack swooped down behind an overturned school bus, where a couple of campers were hiding. Annabeth and I leaped off as soon as our pegasi's hooves touched the pavement. Then Blackjack and Porkpie soared into the night sky.

Michael Yew ran up to us. He was definitely the shortest commando I'd ever seen. He had a bandaged cut on his arm. His ferrety face was smeared with soot and his quiver was almost empty, but he was smiling like he was having a great time.

"Glad you could join us," he said. "Where are the other reinforcements?"

"For now, we're it," I said.

"Then we're dead," he said.

"You still have your flying chariot?" Annabeth asked.

"Nah," Michael said. "Left it at camp. I told Clarisse she could have it. Whatever, you know? Not worth fighting about anymore. But she said it was too late. We'd insulted her honor for the last time or some stupid thing."

"Least you tried," I said.

Michael shrugged. "Yeah, well, I called her some names when she said she still wouldn't fight. I doubt that helped. Here come the uglies!"

He drew an arrow and launched it toward the enemy. The arrow made a screaming sound as it flew. When it landed, it unleashed a blast like a power chord on an electric guitar magnified through the world's largest speakers. The nearest cars exploded. Monsters dropped their weapons and clasped their ears in pain. Some ran. Others disintegrated on the spot.

"That was my last sonic arrow," Michael said.

"A gift from your dad?" I asked. "God of music?"

Michael grinned wickedly. "Loud music can be bad for you. Unfortunately, it doesn't always kill."

Sure enough, most monsters were regrouping, shaking off their confusion.

"We have to fall back," Michael said. "I've got Kayla and Austin setting traps farther down the bridge."

"No," I said. "Bring your campers forward to this position and wait for my signal. We're going to drive the enemy back to Brooklyn."

Michael laughed. "How do you plan to do that?"

I drew my sword.

"Percy," Annabeth said, "let me come with you."

"Too dangerous," I said. "Besides, I need you to help Michael coordinate the defensive line. I'll distract the monsters. You group up here. Move the sleeping mortals out of the way. Then you can start picking off monsters while I keep them focused on me. If anybody can do all that, you can."

Michael snorted. "Thanks a lot."

I kept my eyes on Annabeth.

She nodded reluctantly. "All right. Get moving."

Before I could lose my courage, I said, "Don't I get a kiss for luck? It's kind of a tradition, right?"

I figured she would punch me. Instead, she drew her knife and stared at the army marching toward us. "Come back alive, Seaweed Brain. Then we'll see."

I figured it was the best offer I would get, so I stepped out from behind the school bus. I walked up the bridge in plain sight, straight toward the enemy.