Grover studied me warily. I hadn't persuaded him that I'd really dropped the Underworld idea. "Not always. We go undercover to a lot of schools. We try to sniff out the half-bloods who have the makings of great heroes. If we find one with a very strong aura, like a child of the Big Three, we alert Chiron. He tries to keep an eye on them, since they could cause really huge problems."

"And you found me. Chiron said you thought I might be something special."

Grover looked as if I'd just led him into a trap. "I didn't… Oh, listen, don't think like that. If you were—you know—you'd never ever be allowed a quest, and I'd never get my license. You're probably a child of Hermes. Or maybe even one of the minor gods, like Nemesis, the god of revenge. Don't worry, okay?"

I got the idea he was reassuring himself more than me.

That night after dinner, there was a lot more excitement than usual.

At last, it was time for capture the flag.

When the plates were cleared away, the conch horn sounded and we all stood at our tables.

Campers yelled and cheered as Annabeth and two of her siblings ran into the pavilion carrying a silk banner. It was about ten feet long, glistening gray, with a painting of a barn owl above an olive tree. From the opposite side of the pavilion, Clarisse and her buddies ran in with another banner, of identical size, but gaudy red, painted with a bloody spear and a boar's head.

I turned to Luke and yelled over the noise, "Those are the flags?"

"Yeah."

"Ares and Athena always lead the teams?"

"Not always," he said. "But often."

"So, if another cabin captures one, what do you do— repaint the flag?"

He grinned. "You'll see. First we have to get one."

"Whose side are we on?"

He gave me a sly look, as if he knew something I didn't. The scar on his face made him look almost evil in the torchlight. "We've made a temporary alliance with Athena. Tonight, we get the flag from Ares. And you are going to help."

The teams were announced. Athena had made an alliance with Apollo and Hermes, the two biggest cabins. Apparently, privileges had been traded—shower times, chore schedules, the best slots for activities—in order to win support.

Ares had allied themselves with everybody else: Dionysus, Demeter, Aphrodite, and Hephaestus. From what I'd seen, Dionysus's kids were actually good athletes, but there were only two of them. Demeter's kids had the edge with nature skills and outdoor stuff but they weren't very aggressive. Aphrodite's sons and daughters I wasn't too worried about. They mostly sat out every activity and checked their reflections in the lake and did their hair and gossiped. Hephaestus's kids weren't pretty, and there were only four of them, but they were big and burly from working in the metal shop all day. They might be a problem. That, of course, left Ares's cabin: a dozen of the biggest, ugliest, meanest kids on Long Island, or anywhere else on the planet.

Chiron hammered his hoof on the marble.

"Heroes!" he announced. "You know the rules. The creek is the boundary line. The entire forest is fair game. All magic items are allowed. The banner must be prominently displayed, and have no more than two guards. Prisoners may be disarmed, but may not be bound or gagged. No killing or maiming is allowed. I will serve as referee and battlefield medic. Arm yourselves!"

He spread his hands, and the tables were suddenly covered with equipment: helmets, bronze swords, spears, oxhide shields coated in metal.

"Whoa," I said. "We're really supposed to use these?"

Luke looked at me as if I were crazy. "Unless you want to get skewered by your friends in cabin five. Here—Chiron thought these would fit. You'll be on border patrol."

My shield was the size of an NBA backboard, with a big caduceus in the middle. It weighed about a million pounds. I could have snowboarded on it fine, but I hoped nobody seriously expected me to run fast. My helmet, like all the helmets on Athena's side, had a blue horsehair plume on top. Ares and their allies had red plumes.

Annabeth yelled, "Blue team, forward!"

We cheered and shook our swords and followed her down the path to the south woods. The red team yelled taunts at us as they headed off toward the north.

I managed to catch up with Annabeth without tripping over my equipment. "Hey."

She kept marching.

"So what's the plan?" I asked. "Got any magic items you can loan me?"

Her hand drifted toward her pocket, as if she were afraid I'd stolen something.

"Just watch Clarisse's spear," she said. "You don't want that thing touching you. Otherwise, don't worry. We'll take the banner from Ares. Has Luke given you your job?"

"Border patrol, whatever that means."

"It's easy. Stand by the creek, keep the reds away. Leave the rest to me. Athena always has a plan."

She pushed ahead, leaving me in the dust.

"Okay," I mumbled. "Glad you wanted me on your team."

It was a warm, sticky night. The woods were dark, with fireflies popping in and out of view. Annabeth stationed me next to a little creek that gurgled over some rocks, then she and the rest of the team scattered into the trees.

Standing there alone, with my big blue-feathered helmet and my huge shield, I felt like an idiot. The bronze sword, like all the swords I'd tried so far, seemed balanced wrong. The leather grip pulled on my hand like a bowling ball.

There was no way anybody would actually attack me, would they? I mean, Olympus had to have liability issues, right?

Far away, the conch horn blew. I heard whoops and yells in the woods, the clanking of metal, kids fighting. A blue-plumed ally from Apollo raced past me like a deer, leaped through the creek, and disappeared into enemy territory.

Great, I thought. I'll miss all the fun, as usual.

Then I heard a sound that sent a chill up my spine, a low canine growl, somewhere close by.

I raised my shield instinctively; I had the feeling something was stalking me.

Then the growling stopped. I felt the presence retreating.

On the other side of the creek, the underbrush exploded. Five Ares warriors came yelling and screaming out of the dark.

"Cream the punk!" Clarisse screamed.

Her ugly pig eyes glared through the slits of her helmet. She brandished a five-foot-long spear, its barbed metal tip flickering with red light. Her siblings had only the standard-issue bronze swords—not that that made me feel any better.

They charged across the stream. There was no help in sight. I could run. Or I could defend myself against half the Ares cabin.

I managed to sidestep the first kid's swing, but these guys were not as stupid the Minotaur. They surrounded me, and Clarisse thrust at me with her spear. My shield deflected the point, but I felt a painful tingling all over my body. My hair stood on end. My shield arm went numb, and the air burned.

Electricity. Her stupid spear was electric. I fell back.

Another Ares guy slammed me in the chest with the butt of his sword and I hit the dirt.

They could've kicked me into jelly, but they were too busy laughing.

"Give him a haircut," Clarisse said. "Grab his hair."

I managed to get to my feet. I raised my sword, but Clarisse slammed it aside with her spear as sparks flew. Now both my arms felt numb.

"Oh, wow," Clarisse said. "I'm scared of this guy. Really scared."

"The flag is that way," I told her. I wanted to sound angry, but I was afraid it didn't come out that way.

"Yeah," one of her siblings said. "But see, we don't care about the flag. We care about a guy who made our cabin look stupid."

"You do that without my help," I told them. It probably wasn't the smartest thing to say.

Two of them came at me. I backed up toward the creek, tried to raise my shield, but Clarisse was too fast. Her spear stuck me straight in the ribs. If I hadn't been wearing an armored breastplate, I would've been shish-ke-babbed. As it was, the electric point just about shocked my teeth out of my mouth. One of her cabinmates slashed his sword across my arm, leaving a good-size cut.