I was staring at the shield when I noticed a strange sound—water gurgling—and I realized there was something new in the room. At the back of the cabin was a big basin of gray sea rock, with a spout like the head of a fish carved in stone. Out of its mouth burst a stream of water, a saltwater spring that trickled into the pool. The water must've been hot, because it sent mist into the cold winter air like a sauna. It made the room feel warm and summery, fresh with the smell of the sea.

I stepped up to the pool. There was no note attached or anything, but I knew it could only be a gift from Poseidon.

I looked into the water and said, "Thanks, Dad."

The surface rippled. At the bottom of the pool, coins shimmered—a dozen or so golden drachma. I realized what the fountain was for. It was a reminder to keep in touch with my family.

I opened the nearest window, and the wintry sunlight made a rainbow in the mist. Then I fished a coin out of the hot water.

"Iris, O Goddess of the Rainbow," I said, "accept my offering."

I tossed a coin into the mist and it disappeared. Then I realized I didn't know who to contact first.

My mom? That would've been the "good son" thing to do, but she wouldn't be worried about me yet. She was used to me disappearing for days or weeks at a time.

My father? It had been way too long, almost two years, since I'd actually talked to him. But could you even send an Iris-message to a god? I'd never tried. Would it make them mad, like a sales call or something?

I hesitated. Then I made up my mind.

"Show me Tyson," I requested. "At the forges of the Cyclopes."

The mist shimmered, and the image of my half brother appeared. He was surrounded in fire, which would've been a problem if he weren't a Cyclops. He was bent over an anvil, hammering a red-hot sword blade. Sparks flew and flames swirled around his body. There was a marble-framed window behind him, and it looked out onto dark blue water—the bottom of the ocean.

"Tyson!" I yelled.

He didn't hear me at first because of the hammering and the roar of the flames.

"TYSON!"

He turned, and his one enormous eye widened. His face broke into a crooked yellow grin. "Percy!"

He dropped the sword blade and ran at me, trying to give me a hug. The vision blurred and I instinctively lurched back. "Tyson, it's an Iris-message. I'm not really here."

"Oh." He came back into view, looking embarrassed. "Oh, I knew that. Yes."

"How are you?" I asked. "How's the job?"

His eye lit up. "Love the job! Look!" He picked up the hot sword blade with his bare hands. "I made this!"

"That's really cool."

"I wrote my name on it. Right there."

"Awesome. Listen, do you talk to Dad much?"

Tyson's smile faded. "Not much. Daddy is busy. He is worried about the war."

"What do you mean?"

Tyson sighed. He stuck the sword blade out the window, where it made a cloud of boiling bubbles. When Tyson brought it back in, the metal was cool. "Old sea spirits making trouble. Aigaios. Oceanus. Those guys."

I sort of knew what he was talking about. He meant the immortals who ruled the oceans back in the days of the Titans. Before the Olympians took over. The fact that they were back now, with the Titan Lord Kronos and his allies gaining strength, was not good.

"Is there anything I can do?" I asked.

Tyson shook his head sadly. "We are arming the mermaids. They need a thousand more swords by tomorrow." He looked at his sword blade and sighed. "Old spirits are protecting the bad boat."

"The Princess Andromeda?" I said. "Luke's boat?"

"Yes. They make it hard to find. Protect it from Daddy's storms. Otherwise he would smash it."

"Smashing it would be good."

Tyson perked up, as if he'd just had another thought. "Annabeth! Is she there?"

"Oh, well…" My heart felt like a bowling ball. Tyson thought Annabeth was just about the coolest thing since peanut butter (and he seriously loved peanut butter). I didn't have the heart to tell him she was missing. He'd start crying so bad he'd probably put out his fires. "Well, no… she's not here right now."

"Tell her hello!" He beamed. "Hello to Annabeth!"

"Okay." I fought back a lump in my throat. "I'll do that."

"And, Percy, don't worry about the bad boat. It is going away."

"What do you mean?"

"Panama Canal! Very far away."

I frowned. Why would Luke take his demon-infested cruise ship all the way down there? The last time we'd seen him, he'd been cruising along the East Coast, recruiting half-bloods and training his monstrous army.

"All right," I said, not feeling reassured. "That's… good. I guess."

In the forges, a deep voice bellowed something I couldn't make out. Tyson flinched. "Got to get back to work! Boss will get mad. Good luck, Brother!"

"Okay, tell Dad—"

But before I could finish, the vision shimmered and faded. I was alone again in my cabin, feeling even lonelier than before.

I was pretty miserable at dinner that night.

I mean, the food was excellent as usual. You can't go wrong with barbecue, pizza, and never-empty soda goblets. The torches and braziers kept the outdoor pavilion warm, but we all had to sit with our cabin mates, which meant I was alone at the Poseidon table. Thalia sat alone at the Zeus table, but we couldn't sit together. Camp rules. At least the Hephaestus, Ares, and Hermes cabins had a few people each. Nico sat with the Stoll brothers, since new campers always got stuck in the Hermes cabin if their Olympian parent was unknown. The Stoll brothers seemed to be trying to convince Nico that poker was a much better game than Mythomagic. I hoped Nico didn't have any money to lose.

The only table that really seemed to be having a good time was the Artemis table. The Hunters drank and ate and laughed like one big happy family. Zoe sat at the head like she was the mama. She didn't laugh as much as the others, but she did smile from time to time. Her silver lieutenant's band glittered in the dark braids of her hair. I thought she looked a lot nicer when she smiled. Bianca di Angelo seemed to be having a great time. She was trying to learn how to arm wrestle from the big girl who'd picked a fight with the Ares kid on the basketball court. The bigger girl was beating her every time, but Bianca didn't seem to mind.

When we'd finished eating, Chiron made the customary toast to the gods and formally welcomed the Hunters of Artemis. The clapping was pretty halfhearted. Then he announced the "good will" capture-the-flag game for tomorrow night, which got a lot better reception.

Afterward, we all trailed back to our cabins for an early, winter lights out. I was exhausted, which meant I fell asleep easily. That was the good part. The bad part was, I had a nightmare, and even by my standards it was a whopper.

Annabeth was on a dark hillside, shrouded in fog. It almost seemed like the Underworld, because I immediately felt claustrophobic and I couldn't see the sky above—just a close, heavy darkness, as if I were in a cave.

Annabeth struggled up the hill. Old broken Greek columns of black marble were scattered around, as though something had blasted a huge building to rums.

"Thorn!" Annabeth cried. "Where are you? Why did you bring me here?" She scrambled over a section of broken wall and came to the crest of the hill.

She gasped.

There was Luke. And he was in pain.

He was crumpled on the rocky ground, trying to rise. The blackness seemed to be thicker around him, fog swirling hungrily. His clothes were in tatters and his face was scratched and drenched with sweat,

"Annabeth!" he called. "Help me! Please!"

She ran forward.

I tried to cry out: He's a traitor! Don't trust him!

But my voice didn't work in the dream.

Annabeth had tears in her eyes. She reached down like she wanted to touch Luke's face, but at the last second she hesitated.