Percy got to his feet. "How could we take offense? You just tried to drown us and suck out our lives."

Hagno winced. "Sorry about that. I was not myself. But you have reminded me of the sun and the rain and the streams in the meadows. Percy and Jason, thanks to you, I remembered the sea and the sky. I am cleansed. But mostly, thanks to Piper. She shared something even better than clear running water." Hagno turned to her. "You have a good nature, Piper. And I'm a nature spirit. I know what I'm talking about."

Hagno pointed to the other side of the room. The stairs to the surface reappeared. Directly underneath, a circular opening shimmered into existence, like a sewer pipe, just big enough to crawl through. Piper suspected this was how the water had drained out.

"You may return to the surface," Hagno said. "Or, if you insist, you may follow the waterway to the giants. But choose quickly, because both doors will fade soon after I am gone. That pipe connects to the old aqueduct line, which feeds both this nymphaeum and the hypogeum that the giants call home."

"Ugh." Percy pressed on his temples. "Please, no more complicated words."

"Oh, home is not a complicated word." Hagno sounded completely sincere. "I thought it was, but now you have unbound us from this place. My sisters have gone to seek new homes...a mountain stream, perhaps, or a lake in a meadow. I will follow them. I cannot wait to see the forests and grasslands again, and the clear running water."

"Uh," Percy said nervously, "things have changed up above in the last few thousand years."

"Nonsense," Hagno said. "How bad could it be? Pan would not allow nature to become tainted. I can't wait to see him, in fact."

Percy looked like he wanted to say something, but he stopped himself.

"Good luck, Hagno," Piper said. "And thank you."

The nymph smiled one last time and vaporized.

Briefly, the nymphaeum glowed with a softer light, like a full moon. Piper smelled exotic spices and blooming roses. She heard distant music and happy voices talking and laughing. She guessed she was hearing hundreds of years of parties and celebrations that had been held at this shrine in ancient times, as if the memories had been freed along with the spirits.

"What is that?" Jason asked nervously.

Piper slipped her hand into his. "The ghosts are dancing. Come on. We'd better go meet the giants."

Percy was tired of water.

If he said that aloud, he would probably get kicked out of Poseidon's Junior Sea Scouts, but he didn't care.

After barely surviving the nymphaeum, he wanted to go back to the surface. He wanted to be dry and sit in the warm sunshine for a long time-preferably with Annabeth.

Unfortunately, he didn't know where Annabeth was. Frank, Hazel, and Leo were missing in action. He still had to save Nico di Angelo, assuming the guy wasn't already dead. And there was that little matter of the giants destroying Rome, waking Gaea, and taking over the world.

Seriously, these monsters and gods were thousands of years old. Couldn't they take a few decades off and let Percy live his life? Apparently not.

Percy took the lead as they crawled down the drainage pipe. After thirty feet, it opened into a wider tunnel. To their left, somewhere in the distance, Percy heard rumbling and creaking, like a huge machine needed oiling. He had absolutely no desire to find out what was making that sound, so he figured that must be the way to go.

Several hundred feet later, they reached a turn in the tunnel. Percy held up his hand, signaling Jason and Piper to wait. He peeked around the corner.

The corridor opened into a vast room with twenty-foot ceilings and rows of support columns. It looked like the same parking-garage-type area Percy had seen in his dreams, but now much more crowded with stuff.

The creaking and rumbling came from huge gears and pulley systems that raised and lowered sections of the floor for no apparent reason. Water flowed through open trenches (oh, great, more water), powering waterwheels that turned some of the machines. Other machines were connected to huge hamster wheels with hellhounds inside. Percy couldn't help thinking of Mrs. O'Leary, and how much she would hate being trapped inside one of those.

Suspended from the ceiling were cages of live animals-a lion, several zebras, a whole pack of hyenas, and even an eight-headed hydra. Ancient-looking bronze and leather conveyor belts trundled along with stacks of weapons and armor, sort of like the Amazons' warehouse in Seattle, except this place was obviously much older and not as well organized.

Leo would love it, Percy thought. The whole room was like one massive, scary, unreliable machine.

"What is it?" Piper whispered.

Percy wasn't even sure how to answer. He didn't see the giants, so he gestured for his friends to come forward and take a look.

About twenty feet inside the doorway, a life-size wooden cutout of a gladiator popped up from the floor. It clicked and whirred along a conveyor belt, got hooked on a rope, and ascended through a slot in the roof.

Jason murmured, "What the heck?"

They stepped inside. Percy scanned the room. There were several thousand things to look at, most of them in motion, but one good aspect of being an ADHD demigod was that Percy was comfortable with chaos. About a hundred yards away, he spotted a raised dais with two empty oversized praetor chairs. Standing between them was a bronze jar big enough to hold a person.

"Look." He pointed it out to his friends.

Piper frowned. "That's too easy."

"Of course," Percy said.

"But we have no choice," Jason said. "We've got to save Nico."

"Yeah." Percy started across the room, picking his way around conveyor belts and moving platforms.

The hellhounds in the hamster wheels paid them no attention. They were too busy running and panting, their red eyes glowing like headlights. The animals in the other cages gave them bored looks, as if to say, I'd kill you, but it would take too much energy.

Percy tried to watch out for traps, but everything here looked like a trap. He remembered how many times he'd almost died in the labyrinth a few years ago. He really wished Hazel were here so she could help with her underground skills (and of course so she could be reunited with her brother).

They jumped over a water trench and ducked under a row of caged wolves. They had made it about halfway to the bronze jar when the ceiling opened over them. A platform lowered. Standing on it like an actor, with one hand raised and his head high, was the purple-haired giant Ephialtes.

Just like Percy had seen in his dreams, the Big F was small by giant standards-about twelve feet tall-but he had tried to make up for it with his loud outfit. He'd changed out of the gladiator armor and was now wearing a Hawaiian shirt that even Dionysus would've found vulgar. It had a garish print made up of dying heroes, horrible tortures, and lions eating slaves in the Colosseum. The giant's hair was braided with gold and silver coins. He had a ten-foot spear strapped to his back, which wasn't a good fashion statement with the shirt. He wore bright white jeans and leather sandals on his...well, not feet, but curved snakeheads. The snakes flicked their tongues and writhed as if they didn't appreciate holding up the weight of a giant.

Ephialtes smiled at the demigods like he was really, really pleased to see them.

"At last!" he bellowed. "So very happy! Honestly, I didn't think you'd make it past the nymphs, but it's so much better that you did. Much more entertaining. You're just in time for the main event!"

Jason and Piper closed ranks on either side of Percy. Having them there made him feel a little better. This giant was smaller than a lot of monsters he had faced, but something about him made Percy's skin crawl. Ephialtes's eyes danced with a crazy light.

"We're here," Percy said, which sounded kind of obvious once he had said it. "Let our friend go."

"Of course!" Ephialtes said. "Though I fear he's a bit past his expiration date. Otis, where are you?"

A stone's throw away, the floor opened, and the other giant rose on a platform.

"Otis, finally!" his brother cried with glee. "You're not dressed the same as me! You're..." Ephialtes's expression turned to horror. "What are you wearing?"

Otis looked like the world's largest, grumpiest ballet dancer. He wore a skin-tight baby-blue leotard that Percy really wished left more to the imagination. The toes of his massive dancing slippers were cut away so that his snakes could protrude. A diamond tiara (Percy decided to be generous and think of it as a king's crown) was nestled in his green, firecracker-braided hair. He looked glum and miserably uncomfortable, but he managed a dancer's bow, which couldn't have been easy with snake feet and a huge spear on his back.

"Gods and Titans!" Ephialtes yelled. "It's showtime! What are you thinking?"

"I didn't want to wear the gladiator outfit," Otis complained. "I still think a ballet would be perfect, you know, while Armageddon is going on." He raised his eyebrows hopefully at the demigods. "I have some extra costumes-"

"No!" Ephialtes snapped, and for once Percy was in agreement.

The purple-haired giant faced Percy. He grinned so painfully, he looked like he was being electrocuted.

"Please excuse my brother," he said. "His stage presence is awful, and he has no sense of style."

"Okay." Percy decided not to comment on the Hawaiian shirt. "Now, about our friend..."

"Oh, him," Ephialtes sneered. "We were going to let him finish dying in public, but he has no entertainment value. He's spent days curled up sleeping. What sort of spectacle is that? Otis, tip over the jar."

Otis trudged over to the dais, stopping occasionally to do a plie. He knocked over the jar, the lid popped off, and Nico di Angelo spilled out. The sight of his deathly pale face and too-skinny frame made Percy's heart stop. Percy couldn't tell whether he was alive or dead. He wanted to rush over and check, but Ephialtes stood in his way.

"Now we have to hurry," said the Big F. "We should go through your stage directions. The hypogeum is all set!"

Percy was ready to slice this giant in half and get out of there, but Otis was standing over Nico. If a battle started, Nico was in no condition to defend himself. Percy needed to buy him some recovery time.

Jason raised his gold gladius. "We're not going to be part of any show," he said. "And what's a hypo-whatever-you-call-it?"

"Hypogeum!" Ephialtes said. "You're a Roman demigod, aren't you? You should know! Ah, but I suppose if we do our job right down here in the underworks, you really wouldn't know the hypogeum exists."

"I know that word," Piper said. "It's the area under a coliseum. It housed all the set pieces and machinery used to create special effects."

Ephialtes clapped enthusiastically. "Exactly so! Are you a student of the theater, my girl?"

"Uh...my dad's an actor."

"Wonderful!" Ephialtes turned toward his brother. "Did you hear that, Otis?"

"Actor," Otis murmured. "Everybody's an actor. No one can dance."

"Be nice!" Ephialtes scolded. "At any rate, my girl, you're absolutely right, but this hypogeum is much more than the stageworks for a coliseum. You've heard that in the old days some giants were imprisoned under the earth, and from time to time they would cause earthquakes when they tried to break free? Well, we've done much better! Otis and I have been imprisoned under Rome for eons, but we've kept busy building our very own hypogeum. Now we're ready to create the greatest spectacle Rome has ever seen-and the last!"

At Otis's feet, Nico shuddered. Percy felt like a hellhound hamster wheel somewhere in his chest had started moving again. At least Nico was alive. Now they just had to defeat the giants, preferably without destroying the city of Rome, and get out of here to find their friends.

"So!" Percy said, hoping to keep the giants' attention on him. "Stage directions, you said?"

"Yes!" Ephialtes said. "Now, I know the bounty stipulates that you and the girl Annabeth should be kept alive if possible, but honestly, the girl is already doomed, so I hope you don't mind if we deviate from the plan."

Percy's mouth tasted like bad nymph water. "Already doomed. You don't mean she's-"

"Dead?" the giant asked. "No. Not yet. But don't worry! We've got your other friends locked up, you see."

Piper made a strangled sound. "Leo? Hazel and Frank?"

"Those are the ones," Ephialtes agreed. "So we can use them for the sacrifice. We can let the Athena girl die, which will please Her Ladyship. And we can use you three for the show! Gaea will be a bit disappointed, but really, this is a win-win. Your deaths will be much more entertaining."

Jason snarled. "You want entertaining? I'll give you entertaining."

Piper stepped forward. Somehow she managed a sweet smile. "I've got a better idea," she told the giants. "Why don't you let us go? That would be an incredible twist. Wonderful entertainment value, and it would prove to the world how cool you are."

Nico stirred. Otis looked down at him. His snaky feet flicked their tongues at Nico's head.

"Plus!" Piper said quickly. "Plus, we could do some dance moves as we're escaping. Perhaps a ballet number!"

Otis forgot all about Nico. He lumbered over and wagged his finger at Ephialtes. "You see? That's what I was telling you! It would be incredible!"

For a second, Percy thought Piper was going to pull it off. Otis looked at his brother imploringly. Ephialtes tugged at his chin as if considering the idea.

At last he shook his head. "No...no, I'm afraid not. You see, my girl, I am the anti-Dionysus. I have a reputation to uphold. Dionysus thinks he knows parties? He's wrong! His revels are tame compared to what I can do. That old stunt we pulled, for instance, when we piled up mountains to reach Olympus-"

"I told you that would never work," Otis muttered.

"And the time my brother covered himself with meat and ran through an obstacle course of drakons-"

"You said Hephaestus-TV would show it during prime time," Otis said. "No one even saw me."

"Well, this spectacle will be even better," Ephialtes promised. "The Romans always wanted bread and circuses-food and entertainment! As we destroy their city, I will offer them both. Behold, a sample!"

Something dropped from the ceiling and landed at Percy's feet: a loaf of sandwich bread in a white plastic wrapper with red and yellow dots.

Percy picked it up. "Wonder bread?"

"Magnificent, isn't it?" Ephialtes's eyes danced with crazy excitement. "You can keep that loaf. I plan on distributing millions to the people of Rome as I obliterate them."

"Wonder bread is good," Otis admitted. "Though the Romans should dance for it."

Percy glanced over at Nico, who was just starting to move. Percy wanted him to be at least conscious enough to crawl out of the way when the fighting started. And Percy needed more information from the giants about Annabeth, and where his other friends were being kept.

"Maybe," Percy ventured, "you should bring our other friends here. You know, spectacular deaths...the more the merrier, right?"

"Hmm." Ephialtes fiddled with a button on his Hawaiian shirt. "No. It's really too late to change the choreography. But never fear. The circuses will be marvelous! Ah...not the modern sort of circus, mind you. That would require clowns, and I hate clowns."

"Everyone hates clowns," Otis said. "Even other clowns hate clowns."

"Exactly," his brother agreed. "But we have much better entertainment planned! The three of you will die in agony, up above, where all the gods and mortals can watch. But that's just the opening ceremony! In the old days, games went on for days or weeks. Our spectacle-the destruction of Rome-will go on for one full month until Gaea awakens."

"Wait," Jason said. "One month, and Gaea wakes up?"

Ephialtes waved away the question. "Yes, yes. Something about August First being the best date to destroy all humanity. Not important! In her infinite wisdom, the Earth Mother has agreed that Rome can be destroyed first, slowly and spectacularly. It's only fitting!"

"So..." Percy couldn't believe he was talking about the end of the world with a loaf of Wonder bread in his hand. "You're Gaea's warm-up act."

Ephialtes's face darkened. "This is no warm-up, demigod! We'll release wild animals and monsters into the streets. Our special effects department will produce fires and earthquakes. Sinkholes and volcanoes will appear randomly out of nowhere! Ghosts will run rampant."

"The ghost thing won't work," Otis said. "Our focus groups say it won't pull ratings."

"Doubters!" Ephialtes said. "This hypogeum can make anything work!"

Ephialtes stormed over to a big table covered with a sheet. He pulled the sheet away, revealing a collection of levers and knobs almost as complicated-looking as Leo's control panel on the Argo II.

"This button?" Ephialtes said. "This one will eject a dozen rabid wolves into the Forum. And this one will summon automaton gladiators to battle tourists at the Trevi Fountain. This one will cause the Tiber to flood its banks so we can reenact a naval battle right in the Piazza Navona! Percy Jackson, you should appreciate that, as a son of Poseidon!"