She'd never ridden a bull before, but she'd practiced bareback pegasus riding at Camp Half-Blood, and she remembered what to do. She used her momentum, swinging one leg over Achelous's back. Then she locked her ankles around his neck, wrapped one arm around his throat, and drew her knife with the other. She pressed the blade under the river god's chin.

"Let-Jason-go." She put all her force into the command. "Now!"

Piper realized there were many flaws in her plan. The river god might simply dissolve into water. Or he could pull her under and wait for her to drown. But apparently her charmspeak worked. Or maybe Achelous was just too surprised to think straight. He probably wasn't used to pretty girls threatening to cut his throat.

Jason shot out of the water like a human cannonball. He broke through the branches of an olive tree and tumbled onto the grass. That couldn't have felt good, but he struggled to his feet, gasping and coughing. He raised his sword, and the dark clouds thickened over the river.

Piper shot him a warning look: Not yet. She still had to get out of this river without drowning or getting electrocuted.

Achelous arched his back as if contemplating a trick. Piper pressed the knife harder against his throat.

"Be a good bull," she warned.

"You promised," Achelous said through gritted teeth. "You promised Hercules wouldn't get my horn."

"And he won't," Piper said. "But I will."

She raised her knife and slashed off the god's horn. The Celestial bronze cut through the base like it was wet clay. Achelous bellowed in rage. Before he could recover, Piper stood up on his back. With the horn in one hand and her dagger in the other, she leaped for the shore.

"Jason!" she yelled.

Thank the gods, he understood. A gust of wind caught her and carried her safely over the bank. Piper hit the ground rolling as the hairs on her neck stood up. A metallic smell filled the air. She turned toward the river in time to be blinded.

BOOM!Lightning stirred the water into a boiling cauldron, steaming and hissing with electricity. Piper blinked the yellow spots out of her eyes as the god Achelous wailed and dissolved beneath the surface. His horrified expression seemed to be asking: How could you?

"Jason, run!" She was still dizzy and sick with fear, but she and Jason crashed through the woods.

As she climbed the hill, clasping the bull's horn to her chest, Piper realized she was sobbing-though she wasn't sure if it was from fear, or relief, or shame for what she'd done to the old river god.

They didn't slow down until they reached the crest of the hill.

Piper felt silly, but she kept breaking down and crying as she told Jason what had happened while he was struggling underwater.

"Piper, you had no choice." He put his hand on her shoulder. "You saved my life."

She wiped her eyes and tried to control herself. The sun was nearing the horizon. They had to get back to Hercules quickly, or their friends would die.

"Achelous forced your hand," Jason continued. "Besides, I doubt that lightning bolt killed him. He's an ancient god. You'd have to destroy his river to destroy him. And he can live without a horn. If you had to lie about not giving it to Hercules, well-"

"I wasn't lying."

Jason stared at her. "Pipes...we don't have a choice. Hercules will kill-"

"Hercules doesn't deserve this." Piper wasn't sure where this rage was coming from, but she had never felt more certain of anything in her life.

Hercules was a bitter, selfish jerk. He'd hurt too many people, and he wanted to keep on hurting them. Maybe he'd had some bad breaks. Maybe the gods had kicked him around. But that didn't excuse it. A hero couldn't control the gods, but he should be able to control himself.

Jason would never be like that. He would never blame others for his problems or make a grudge more important than doing the right thing.

Piper was not going to repeat Deianira's story. She wasn't going to go along with what Hercules wanted just because he was handsome and strong and scary. He couldn't get his way this time-not after threatening their lives and sending them to make Achelous miserable for the sake of spiting Hera. Hercules didn't deserve a horn of plenty. Piper was going to put him in his place.

"I have a plan," she said.

She told Jason what to do. She didn't even realize she was using charmspeak until his eyes glazed over.

"Whatever you say," he promised. Then he blinked a few times. "We're going to die, but I'm in."

Hercules was waiting right where they'd left him. He was staring at the Argo II, docked between the pillars as the sun set behind it. The ship looked okay, but Piper's plan had started to feel insane to her.

Too late to reconsider. She'd already sent an Iris-message to Leo. Jason was prepared. And, seeing Hercules again, she felt more certain than ever she couldn't give him what he wanted.

Hercules didn't exactly brighten when he saw Piper carrying the bull's horn, but his scowl lines lessened.

"Good," he said. "You got it. In that case, you are free to go."

Piper glanced at Jason. "You heard him. He gave us permission." She turned back to the god. "That means our ship will be able to pass into the Mediterranean?"

"Yes, yes." Hercules snapped his fingers. "Now, the horn."

"No," Piper said.

The god frowned. "Excuse me?"

She raised the cornucopia. Since she'd cut it from Achelous's head, the horn had hollowed out, becoming smooth and dark on the inside. It didn't appear magical, but Piper was counting on its power.

"Achelous was right," she said. "You're his curse as much as he is yours. You're a sorry excuse for a hero."

Hercules stared at her as if she were speaking in Japanese. "You realize I could kill you with a flick of my finger," he said. "I could throw my club at your ship and cut straight through its hull. I could-"

"You could shut up," Jason said. He drew his sword. "Maybe Zeus is different from Jupiter. Because I wouldn't put up with any brother who acts like you."

The veins on Hercules's neck turned as purple as his robes. "You would not be the first demigod I've killed."

"Jason is better than you," Piper said. "But don't worry. We're not going to fight you. We're going to leave this island with the horn. You don't deserve it as a prize. I'm going to keep it, to remind me of what not to be like as a demigod, and to remind me of poor Achelous and Deianira."

The god's nostrils flared. "Do not mention that name! You can't seriously think I'm worried about your puny boyfriend. No one is stronger than me."

"I didn't say stronger," Piper corrected. "I said he's better."

Piper pointed the mouth of the horn at Hercules. She let go of the resentment and doubt and anger she'd been harboring since Camp Jupiter. She concentrated on all the good things she'd shared with Jason Grace: soaring upward in the Grand Canyon, walking on the beach at Camp Half-Blood, holding hands at the sing-along and watching the stars, sitting by the strawberry fields together on lazy afternoons and listening to the satyrs play their pipes.

She thought about a future when the giants had been defeated, Gaea was asleep, and they would live happily together-no jealousy, no monsters left to battle. She filled her heart with those thoughts, and she felt the cornucopia grow warm.

The horn blasted forth a flood of food as powerful as Achelous's river. A torrent of fresh fruit, baked goods, and smoked hams completely buried Hercules. Piper didn't understand how all that stuff could fit through the entrance of the horn, but she thought the hams were especially appropriate.

When it had spewed out enough goodies to fill a house, the horn shut itself off. Piper heard Hercules shrieking and struggling somewhere underneath. Apparently even the strongest god in the world could be caught off guard when buried under fresh produce.

"Go!" she told Jason, who'd forgotten his part of the plan and was staring in amazement at the fruit pile. "Go!"

He grabbed Piper's waist and summoned the wind. They shot away from the island so quickly, Piper almost got whiplash; but it wasn't a second too soon.

As the island retreated from view, Hercules's head broke above the mound of goodies. Half a coconut was stuck on his noggin like a war helmet. "Kill!" he bellowed, like he'd had a lot of practice saying it.

Jason touched down on the deck of the Argo II. Thankfully, Leo had done his part. The ship's oars were already in aerial mode. The anchor was up. Jason summoned a gale so strong, it pushed them into the sky, while Percy sent a ten-foot-tall wave against the shore, knocking Hercules down a second time, in a cascade of seawater and pineapples.

By the time the god regained his feet and started lobbing coconuts at them from far below, the Argo II was already sailing through the clouds above the Mediterranean.

Percy was not feeling the love.

Bad enough he'd been run out of Atlanta by evil sea gods. Then he had failed to stop a giant shrimp attack on the Argo II. Then the ichthyocentaurs, Chiron's brothers, hadn't even wanted to meet him.

After all that, they had arrived at the Pillars of Hercules, and Percy had to stay aboard ship while Jason the Big Shot visited his half brother. Hercules, the most famous demigod of all time, and Percy didn't get to meet him either.

Okay, sure, from what Piper said afterward, Hercules was a jerk, but still...Percy was getting kind of tired of staying aboard ship and pacing the deck.

The open sea was supposed to be his territory. Percy was supposed to step up, take charge, and keep everybody safe. Instead, all the way across the Atlantic, he'd done pretty much nothing except make small talk with sharks and listen to Coach Hedge sing TV theme songs.

To make matters worse, Annabeth had been distant ever since they had left Charleston. She spent most of her time in her cabin, studying the bronze map she'd retrieved from Fort Sumter, or looking up information on Daedalus's laptop.

Whenever Percy stopped by to see her, she was so lost in thought that the conversation went something like this: Percy: "Hey, how's it going?"

Annabeth: "Uh, no thanks."

Percy: "Okay...have you eaten anything today?"

Annabeth: "I think Leo is on duty. Ask him."

Percy: "So, my hair is on fire."

Annabeth: "Okay. In a while."

She got like this sometimes. It was one of the challenges of dating an Athena girl. Still, Percy wondered what he had to do to get her attention. He was worried about her after her encounter with the spiders at Fort Sumter, and he didn't know how to help her, especially if she shut him out.

After leaving the Pillars of Hercules-unscathed except for a few coconuts lodged in the hull's bronze plating-the ship traveled by air for a few hundred miles.

Percy hoped the ancient lands wouldn't be as bad as they'd heard. But it was almost like a commercial: You'll notice the difference immediately!

Several times an hour, something attacked the ship. A flock of flesh-eating Stymphalian birds swooped out of the night sky, and Festus torched them. Storm spirits swirled around the mast, and Jason blasted them with lightning. While Coach Hedge was having dinner on the foredeck, a wild pegasus appeared from nowhere, stampeded over the coach's enchiladas, and flew off again, leaving cheesy hoof prints all across the deck.

"What was that for?" the coach demanded.

The sight of the pegasus made Percy wish Blackjack were here. He hadn't seen his friend in days. Tempest and Arion also hadn't shown themselves. Maybe they didn't want to venture into the Mediterranean. If so, Percy couldn't blame them.

Finally around midnight, after the ninth or tenth aerial attack, Jason turned to him. "How about you get some sleep? I'll keep blasting stuff out of the sky as long as I can. Then we can go by sea for a while, and you can take point."

Percy wasn't sure that he'd be able to sleep with the boat rocking through the clouds as it was shaken by angry wind spirits, but Jason's idea made sense. He went belowdecks and crashed on his bunk.

His nightmares, of course, were anything but restful.

He dreamed he was in a dark cavern. He could only see a few feet in front of him, but the space must have been vast. Water dripped from somewhere nearby, and the sound echoed off distant walls. The way the air moved made Percy suspect the cave's ceiling was far, far above.

He heard heavy footsteps, and the twin giants Ephialtes and Otis shuffled out of the gloom. Percy could distinguish them only by their hair-Ephialtes had the green locks braided with silver and gold coins; Otis had the purple ponytail braided with...were those firecrackers?

Otherwise they were dressed identically, and their outfits definitely belonged in a nightmare. They wore matching white slacks and gold buccaneer shirts with V-necks that showed way too much chest hair. A dozen sheathed daggers lined their rhinestone belts. Their shoes were open-toed sandals, proving that-yes, indeed-they had snakes for feet. The straps wrapped around the serpents' necks. Their heads curled up where the toes should be. The snakes flicked their tongues excitedly and turned their gold eyes in every direction, like dogs looking out the window of a car. Maybe it had been a long time since they'd had shoes with a view.

The giants stood in front of Percy, but they paid him no attention. Instead, they gazed up into the darkness.

"We're here," Ephialtes announced. Despite his booming voice, his words dissipated in the cavern, echoing until they sounded small and insignificant.

Far above, something answered, "Yes. I can see that. Those outfits are hard to miss."

The voice made Percy's stomach drop about six inches. It sounded vaguely female, but not at all human. Each word was a garbled hiss in multiple tones, as if a swarm of African killer bees had learned to speak English in unison.

It wasn't Gaea. Percy was sure of that. But whatever it was, the twin giants became nervous. They shifted on their snakes and bobbed their heads respectfully.

"Of course, Your Ladyship," Ephialtes said. "We bring news of-"

"Why are you dressed like that?" asked the thing in the dark. She didn't seem to be coming any closer, which was fine with Percy.

Ephialtes shot his brother an irritated look. "My brother was supposed to wear something different. Unfortunately-"

"You said I was the knife thrower today," Otis protested.

"I said I was the knife thrower! You were supposed to be the magician! Ah, forgive me, Your Ladyship. You don't want to hear us arguing. We came as you requested, to bring you news. The ship is approaching."

Her Ladyship, whatever she was, made a series of violent hisses like a tire being slashed repeatedly. With a shudder, Percy realized she was laughing.

"How long?" she asked.

"They should land in Rome shortly after daybreak, I think," Ephialtes said. "Of course, they'll have to get past the golden boy."

He sneered, as if the golden boy was not his favorite person.

"I hope they arrive safely," Her Ladyship said. "It would spoil our fun to have them captured too soon. Are your preparations made?"

"Yes, Your Ladyship." Otis stepped forward, and the cavern trembled. A crack appeared under Otis's left snake.

"Careful, you dolt!" Her Ladyship snarled. "Do you want to return to Tartarus the hard way?"

Otis scrambled back, his face slack with terror. Percy realized that the floor, which looked like solid stone, was more like the glacier he'd walked on in Alaska-in some places solid, in other places...not so much. He was glad he weighed nothing in his dreams.

"There is little left holding this place together," Her Ladyship cautioned. "Except, of course, my own skill. Centuries of Athena's rage can only be contained so well, and the great Earth Mother churns below us in her sleep. Between those two forces, well...my nest has quite eroded. We must hope this child of Athena proves to be a worthy victim. She may be my last plaything."

Ephialtes gulped. He kept his eyes on the crack in the floor. "Soon it will not matter, Your Ladyship. Gaea will rise, and we all will be rewarded. You will no longer have to guard this place, or keep your works hidden."

"Perhaps," said the voice in the dark. "But I will miss the sweetness of my revenge. We have worked well together over the centuries, have we not?"

The twins bowed. The coins glittered in Ephialtes's hair, and Percy realized with nauseating certainty that some of them were silver drachma, exactly like the one Annabeth had gotten from her mom.