UNTIL I MET THE EXPLODING STATUE, I thought I was prepared for anything.

I'd paced the deck of their flying warship, the Argo II, checking and double-checking the ballistae to make sure they were locked down. I confirmed that the white "We come in peace" flag was flying from the mast. Annnabeth reviewed the plan with the rest of the crew—and the backup plan, and the backup plan for the backup plan

Most important, I pulled aside our war-crazed chaperone, Coach Gleeson Hedge, and encouraged him to take the morning off in his cabin and watch reruns of mixed martial arts championships. The last thing they needed as they flew a magical Greek trireme into a potentially hostile Roman camp was a middle-aged satyr in gym clothes waving a club and yelling "Die!"

Everything seemed to be in order. Even that mysterious chill I'd been feeling since the ship launched had dissipated, at least for now.

The warship descended through the clouds, but I couldn't stop second-guessing myself. What if this was a bad idea? What if the Romans panicked and attacked us on sight?

The Argo II definitely did not look friendly. Two hundred feet long, with a bronze-plated hull, mounted repeating crossbows fore and aft, a flaming metal dragon for a figurehead, and two rotating ballistae amidships that could fire explosive bolts powerful enough to blast through concrete...well, it wasn't the most appropriate ride for a meet-and-greet with our age old enemies. .

Annabeth had tried to give the Romans a heads-up. She'd asked Leo to send one of his special inventions—a holographic scroll—to alert their friends inside the camp, which I had accidentally interrupted. Hopefully the message had gotten through. Leo had wanted to paint a giant message on the bottom of the hull—WASSUP? with a smiley face—but I vetoed the idea. It sounded passive aggressive, something I would do to Demeter or when crashing Olympus, not going to make amends. I didn't want them getting the wrong idea.

Too late to turn back now.

The clouds broke around their hull, revealing the gold-and-green carpet of the Oakland Hills below them. Annabeth gripped one of the bronze shields that lined the starboard rail and I floated next to her.

Our three crewmates took their places.

On the stern quarterdeck, Leo rushed around like a madman, checking his gauges and wrestling levers. Most helmsmen would've been satisfied with a pilot's wheel or a tiller. Leo had also installed a keyboard, monitor, aviation controls from a Learjet, a dubstep soundboard, and motion-control sensors from a Nintendo Wii. He could turn the ship by pulling on the throttle, fire weapons by sampling an album, or raise sails by shaking his Wii controllers really fast. Even by demigod standards, Leo was seriously ADHD.

Piper paced back and forth between the mainmast and the ballistae, practicing her lines.

"Lower your weapons," she murmured. "We just want to talk."

Her charmspeak was so powerful, the words flowed over me, filling me with the desire to drop my sword, remove my whip and have a nice long chat.

For a child of Aphrodite, Piper tried hard to play down her beauty. Today she was dressed in tattered jeans, worn-out sneakers, and a white tank top with pink Hello Kitty designs. (Maybe as a joke, though I could never be sure with Piper.) Her choppy brown hair was braided down the right side with an eagle's feather.

Then there was Piper's boyfriend—Jason. He stood at the bow on the raised crossbow platform, where the Romans could easily spot him. His knuckles were white on the hilt of his golden sword. Otherwise he looked calm for a guy who was making himself a target. Over his jeans and orange Camp Half-Blood T-shirt, he'd donned a toga and a purple cloak—symbols of his old rank as praetor. With his wind-ruffled blond hair and his icy blue eyes, he looked ruggedly handsome and in control— just like a son of Jupiter should. He'd grown up at Camp Jupiter, so hopefully his familiar face would make the Romans hesitant to blow the ship out of the sky.

I tried to hide it, but I still didn't trust the guy, like at all. He acted too perfect— always following the rules, always doing the honorable thing. He even looked too perfect. In the back of my mind, I had a nagging thought: What if this is a trick and he betrays us? What if we sail into Camp Jupiter, and he says, Hey, Romans! Check out these prisoners and this cool ship I brought you!

I told my best friend about it but Annabeth doubted that would happen. Still, I couldn't look at him without getting a bitter taste in my mouth. He'd been part of Hera's forced "exchange program" to introduce the two camps. Her Most Bitchy Ass Majesty, Queen of Olympus, had convinced the other gods that their two sets of children—Roman and Greek—had to combine forces to save the world from the evil goddess Gaea, who was awakening from the earth, and her horrible children the giants.

Without warning, Hera had plucked up Percy,my boyfriend, wiped his memory, and sent him to the Roman camp. In exchange, the Greeks had gotten Jason. None of that was Jason's fault; but every time I saw him, my heart ached for the boy.

Percy... who was somewhere below them right now.

Oh, gods. Panic welled up inside me. What if he didn't remember me? I don't even know what to say. I forced it down. I can't afford to get overwhelmed.

I'm a child of Hades. I have to control myself.

I felt it again—that familiar shiver, as if a psychotic snowman had crept up behind me and was breathing down my neck. I turned, but no one was there.

Must be my nerves. Even in a world of gods and monsters, I couldn't believe a new warship would be haunted. The Argo II was well protected. The Celestial bronze shields along the rail were enchanted to ward off monsters, and their onboard satyr, Coach Hedge, would have sniffed out any intruders.

The cold pressed closer. She thought she heard a faint voice in the wind, laughing. Every muscle in her body tensed. Something was about to go terribly wrong.

I almost ordered Leo to reverse course. Then, in the valley below, horns sounded. The Romans had spotted them.

I thought I knew what to expect. Jason had described Camp Jupiter to her in great detail. Still, I had trouble believing my eyes. Ringed by the Oakland Hills, the valley was at least twice the size of Camp Half-Blood. A small river snaked around one side and curled toward the center like a capital letter G, emptying into a sparkling blue lake. It looked nothing like Camp and it had me longing for home.

Directly below the ship, nestled at the edge of the lake, the city of New Rome gleamed in the sunlight. I recognized landmarks Jason had told Annabeth and I about—the hippodrome, the coliseum, the temples and parks, the neighborhood of Seven Hills with its winding streets, colorful villas, and flowering gardens.

I even saw evidence of the Romans' recent battle with an army of monsters. The dome was cracked open on a building she guessed was the Senate House. The forum's broad plaza was pitted with craters. Some fountains and statues were in ruins.

Dozens of kids in togas were streaming out of the Senate House to get a better view of the Argo II. More Romans emerged from the shops and cafés, gawking and pointing as the ship descended.

About half a mile to the west, where the horns were blowing, a Roman fort stood on a hill. It looked just like the illustrations I had seen in military history books, Caelan used to be obsessed with them—with a defensive trench lined with spikes, high walls, and watchtowers armed with scorpion ballistae. Inside, perfect rows of white barracks lined the main road—the Via Principalis.

A column of demigods emerged from the gates, their armor and spears glinting as they hurried toward the city. In the midst of their ranks was an actual war elephant.

I wanted to land the Argo II before those troops arrived, but the ground was still several hundred feet below. I scanned the crowd, hoping to catch a glimpse of Percy.

Then something behind me went BOOM!

THE EXPLOSION SENT ME flying overboard but I quickly righted myself. I sped back to the ship and found myself eye to eye with an angry statue.

"Unacceptable!" he shrieked.

Apparently he had exploded into existence, right there on the deck. Sulfurous yellow smoke rolled off his shoulders. Cinders popped around his curly hair. From the waist down, he was nothing but a square marble pedestal. From the waist up, he was a muscular human figure in a carved toga.

"I will not have weapons inside the Pomerian Line!" he announced in a fussy teacher voice. "I certainly will not have Greeks!"

"Well, tough luck. Cause I'm both." I muttered under my breath and he turned a disapproving eye on me.

"You must be the sister the boys are talking about." He sniffed.

"Boys? I only have one brother." My eyebrows furrowed.

"Sure, little missy, sure."

Jason shot me a look that said, I've got this.

"Terminus," he said. "It's me. Jason Grace."

"Oh, I remember you, Jason!" Terminus grumbled. "I thought you had better sense than to consort with the enemies of Rome!"

"But they're not enemies—"

"That's right," Piper jumped in. "We just want to talk. If we could—"

"Ha!" snapped the statue. "Don't try that charmspeak on me, young lady. And put down that dagger before I slap it out of your hands!"

Piper glanced at her bronze dagger, which she'd apparently forgotten she was holding. "Um...okay. But how would you slap it? You don't have any arms."

"Impertinence!" There was a sharp POP and a flash of yellow. Piper yelped and dropped the dagger, which was now smoking and sparking.

"Lucky for you I've just been through a battle," Terminus announced. "If I were at full strength, I would've blasted this flying monstrosity out of the sky already!"

"Hold up." Leo stepped forward, wagging his Wii controller. "Did you just call my ship a monstrosity? I know you didn't do that."

"Leo. I know we all want to but please don't attack the statue with the Wii controller. We kinda need to get into the city." I muttered, rubbing the bridge of my nose. This was going horribly.

The idea that Leo might attack the statue with his gaming device was enough to snap Annabeth out of her shock.

"Let's all calm down." She raised her hands to show she had no weapons. "I take it you're Terminus, the god of boundaries. Jason told me you protect the city of New Rome, right? I'm Annabeth Chase, daughter of—"

"Oh, I know who you are!" The statue glared at her with its blank white eyes. "A child of Athena, Minerva's Greek form. Scandalous! You Greeks have no sense of decency. We Romans know the proper place for that goddess."

Annabeth clenched her jaw. This statue wasn't making it easy to be diplomatic for any of us. "What exactly do you mean, that goddess? And what's so scandalous about—"

"Right!" Jason interrupted. "Anyway, Terminus, we're here on a mission of peace. We'd love permission to land so we can—"

"Impossible!" the god squeaked. "Lay down your weapons and surrender! Leave my city immediately!"

"Which is it?" Leo asked. "Surrender, or leave?"

"Both!" Terminus said. "Surrender, then leave. I am slapping your face for asking such a stupid question, you ridiculous boy! Do you feel that?"

"You're getting on my nerves dude and I deal with Hades and Demeter arguing all the time." I told him and he once again glared at me but stayed silent.

"Wow." Leo studied Terminus with professional interest. "You're wound up pretty tight. You got any gears in there that need loosening? I could take a look."

He exchanged the Wii controller for a screwdriver from his magic tool belt and tapped the statue's pedestal.

"Stop that!" Terminus insisted. Another small explosion made Leo drop his screwdriver. "Weapons are not allowed on Roman soil inside the Pomerian Line."

"The what?" Piper asked.

"City limits," Jason translated.

"And this entire ship is a weapon!" Terminus said. "You cannot land!"

Down in the valley, the legion reinforcements were halfway to the city. The crowd in the forum was over a hundred strong now. I scanned the faces and...oh, gods of Olympus. I saw him. He was walking toward the ship with his arms around two other kids like they were best buddies—a stout boy with a black buzz cut, and a girl wearing a Roman cavalry helmet. Percy looked so at ease, so happy. He wore a purple cape just like Jason's—the mark of a praetor.

My heart did a gymnastics routine against my stomach. My heart was currently winning, thankfully.

"Leo, stop the ship," I ordered.

"What?"

"You heard me. Keep us right where we are."

Leo pulled out his controller and yanked it upward. All ninety oars froze in place. The ship stopped sinking.

"Terminus," I said, "there's no rule against hovering over New Rome, is there?"

The statue frowned. "Well, no..."

"Great! We can keep the ship aloft," I said. "We'll use a rope ladder to reach the forum. That way, the ship won't be on Roman soil. Not technically."

The statue seemed to ponder this. Annabeth wondered if he was scratching his chin with imaginary hands.

"I like technicalities," he admitted. "Still..."

"All our weapons will stay aboard the ship," Annabeth promised. "I assume the Romans—even those reinforcements marching toward us—will also have to honor your rules inside the Pomerian Line if you tell them to?"

"Of course!" Terminus said. "Do I look like I tolerate rule breakers?"

"Uh, Annabeth, Nova..." Leo said. "You sure this is a good idea?"

I closed my fists to keep them from shaking. That cold feeling was still there. It floated just behind me, and now that Terminus was no longer shouting and causing explosions, I thought I could hear the presence laughing, as if it was delighted by the bad choices I was making.

But Percy was down there...he was so close. I had to reach him.

"It'll be fine," I said. "No one will be armed. We can talk in peace. Terminus will make sure each side obeys the rules." She looked at the marble statue. "Do we have an agreement?"

Terminus sniffed. "I suppose. For now. You may climb down your ladder to New Rome, daughter of Athena, daughter of Hades. Please try not to destroy my town."