THE NEXT MORNING Kat woke to a different ship's horn — a blast so loud it surprisingly woke her up. Most of the time, she slept like the dead. But maybe that was because Piper, who had been in her arms, had fallen out of the bed.

Kat sat up and laughed at Piper, who glowered at her like an angry chihuahua, when the horn boomed again. It sounded like it was coming from several hundred yards away — from another vessel.

"Come on!" Piper got to her feet and went to go to her room.

Kat, with her super speed powers, sped out of bed and grabbed a hoodie, yeeting it at her girlfriend. "Just put that on," she said, grabbing her ruby pendant. Well, at least it wasn't glowing. She put it on because she felt like it. "Looks better on you, anyway. Also, who cares about how they're dressed?"

"I do!" Piper argued, but she put on the hoodie anyway and they went out the door. By the time they got up on deck, the others had already gathered — all hastily dressed except for Hedge, who had pulled the night watch.

Frank's Vancouver Winter Olympics shirt was inside out. Percy wore pajama pants and a bronze breastplate, which was an interesting fashion statement. Hazel's hair was all blown to one side, as though she'd walked through a cyclone, which was honestly probably what Kat was looking like right now, but she hadn't checked; and Leo had accidentally set himself on fire. His T-shirt was in charred tatters. His arms were smoking.

About a hundred yards to port, a massive cruise ship glided past. Tourists waved at them from fifteen or sixteen rows of balconies. Some smiled and took pictures. None of them looked surprised to see an Ancient Greek trireme. Maybe the Mist made it look like a fishing boat, or perhaps the cruisers thought the Argo II was a tourist attraction.

The cruise ship blew its horn again, and the Argo II had a shaking fit.

Hedge plugged his ears. "Do they have to be so loud?"

"They're just saying hi," speculated Bumblebee.

"WHAT?" Hedge yelled back.

The ship edged past them, heading out to sea. The tourists kept waving. If they found it strange that the Argo II was populated by half-asleep kids in armor and pajamas and a man with goat legs, they didn't let on.

"Bye!" Leo called, raising his smoking hand.

"Can I man the ballistae?" Hedge asked.

"No," Leo said through a forced smile.

Hazel rubbed her eyes and looked across the glittering green water. "Where are — oh . . . Wow."

Kat followed her gaze and whistled. Without the cruise ship blocking their view, she saw a mountain jutting from the sea less than half a mile to the north. She had seen impressive cliffs before. She'd gone to crystal cliffs and on hikes with Foo Foo Bear. She'd fallen down the Grand Canyon with Jason and flown back up. But none of them were as amazing as this massive fist of blinding white rock thrust into the sky. On one side, the limestone cliffs were almost completely sheer, dropping into the sea over a thousand feet below, as near as Kat could figure. On the other side, the mountain sloped in tiers, covered in green forest, so that the whole thing reminded her of a colossal sphinx, worn down over the millennia, with a massive white head and chest, and a green cloak over its back.

"The Rock of Gibraltar," Kat said, because she basically had GPS powers as a daughter of Hermes, and she'd use them as much as she fucking wants, damn it. "At the tip of Spain. And over there—" She nodded south, to a more distant stretch of red and ochre hills. "That's Africa. We're at the mouth of the Mediterranean."

"Alright, Google Maps," commented Leo, and Kat stuck out her tongue at him.

"You wish you could be as powerful as me," she smirked.

"What now?" asked Piper, nudging Kat in the ribs. "Do we just sail in?"

"Why not?" said Leo. "It's a big shipping channel. Boats go in and out all the time."

"In the old days," Annabeth started, and Kat immediately rolled her eyes. Here we go, lecture time. At least Kat makes it cool. "They called this area the pillars of Hercules. The Rock was supposed to be one pillar. The other was one of the African mountains. Nobody is sure which one."

"Hercules, huh?" Percy frowned. "That guy was like the Starbucks of Ancient Greece. Everywhere you turn — there he is."

"Which is stupid," added Kat. "My ancestor? Way fucking cooler than him."

A thunderous boom shook the Argo II, though Kat wasn't sure where it came from this time. She didn't see any other ships, and the skies were clear. Should she not have said that? Too late for that now.

"So . . . these Pillars of Hercules," Piper ventured. "Are they dangerous?"

Annabeth focused on the white cliffs, as if waiting for the Mark of Athena to blaze to life. "For Greeks, the pillars marked the end of the known world. The Romans said the pillars were inscribed with a Latin warning—"

"Non plus ultra," interrupted Percy.

Annabeth looked stunned. "Yeah. Nothing Further Beyond. How did you know?"

Percy pointed. "Because I'm looking at it."

Directly ahead of them, in the middle of the straits, an island had shimmered into existence. Kat was positive no island had been there before. It was a small hilly mass of land, covered in forests and ringed with white beaches. Not very impressive compared to Gibraltar, but in front of the island, jutting from waves about a hundred yards offshore, were two white Grecian columns as tall as the Argo's masts. Between the columns, huge silver words glittered underwater — maybe an illusion, or maybe inlaid in the sand: NON PLUS ULTRA.

"Guys, do I turn around?" Leo asked nervously. "Or . . ."

No one answered — maybe because, like Kat, who was an obvious genius, they had noticed the figure standing on the beach. As the ship approached the columns, she saw a dark-haired man in purple robes, his arms crossed, staring intently at their ship as if he were expecting them. Kat couldn't tell much else about him from this distance, but judging from his posture, he wasn't happy.

Frank inhaled sharply. "Could that be—?"

"Hercules," Jason said gravely. "The most powerful demigod of all time."

The Argo II was only a few hundred yards from the columns now.

"Need an answer," Leo said urgently. "I can turn, or we can take off. The stabilizers are working again. But I need to know quick—"

"We have to keep going," Annabeth said. "I think he's guarding these straits. If that's really Hercules, sailing or flying away wouldn't do any good. He'll want to talk to us."

Kat resisted the urge to persuade Leo. She wanted to yell at him: Don't listen to her! Get the fuck out of here! Unfortunately, she had a feeling that Annabeth was right. If they wanted to pass into the Mediterranean, they couldn't avoid this meeting.

"Won't Hercules be on our side?" Piper asked hopefully. "I mean . . . he's one of us, right?"

Jason grunted. "He was a son of Zeus, but when he died, he became a god. You can never be sure with gods."

Kat remembered their meeting with Bacchus in Kansas — another god who used to be a demigod. He hadn't been exactly helpful.

"Great," Percy said. "Eight of us against Hercules."

"And a satyr!" Hedge added. "We can take him."

"I've got a better idea," Annabeth said. "We send ambassadors ashore. A smaller group — two or three at most. Try to talk with him."

"I'll go," Jason said. "He's a son of Zeus. I'm the son of Jupiter. Maybe he'll be friendly to me."

"Or maybe he'll hate you," Percy suggested. "Half brothers don't always get along."

Jason scowled. "Thank you, Mr. Optimism."

"It's worth a shot," Annabeth said. "At least Jason and Hercules have something in common. Like him and Kat." She turned to Kat, raising her eyebrows at her. "Your ancestor fought with him, right?"

That didn't really seem like a question.

"Unfortunately," Kat sighed. "This'll be a disaster, but, hey, those are my favorite kinds of dates." She winked at Jason, who pointedly looked away from her, but she could see his cheeks flush because of his pale ass skin.

Annabeth nodded. "And we need our best diplomat. Somebody who's good with words."

All eyes turned to Piper.

"Fine," she said. "Just let me change my clothes."

"Aw, but I like your outfit," Kat pouted. "It really suits you."

Hazel frowned. "Wasn't she wearing that two days ago?"

"My sweet Hazelnut, I can't control the fact that it was thrown over my chair," Kat smirked, before starting to follow Piper down. "I'm gonna grab an energy drink because there's no way I'm surviving this talk otherwise. Cya!"

Once Leo had anchored the Argo II between the pillars, Jason summoned the wind to carry him, Piper, and Kat ashore.

The man in purple was waiting for them.

And, honestly? Hercules wasn't all that impressive. Kat totally isn't biased at all. Not. At. All.

His feet were bare, covered in white sand. Which, ew. His robes made him look like a priest. His beard was fashionably scruffy, like the ones Connor and Travis attempted to have before shaving them off for the Titan War. ( That was a low point ).

Hercules was well built, but not too stocky. His ebony hair was close-cropped, Roman style. He had startling blue eyes like Jason's, but his skin was coppery, as if he'd spent his entire life on a tanning bed. The most surprising thing: he looked about twenty. Definitely no older. He was handsome in a rugged but not-at-all-caveman way. Not Kat's type though.

He did in fact have a club, which lay in the sand next to him, but it was more like an oversized baseball bat — a five-foot-long polished cylinder of mahogany with a leather handgrip studded in bronze. Hedge would have been jealous.

Kat, Jason, and Piper landed at the edge of the surf. They approached slowly, careful not to make any threatening moves. Hercules watched them with no particular emotion, as if they were some form of seabird he had never noticed before.

"Hello," Piper said.

"What's up?" Hercules said. His voice was deep but casual, very modern. He could've been greeting them in the high school locker room.

"Uh, not much." Piper winced. "Well, actually, a lot. I'm Piper. This is Jason, and that's Kat. We—"

"Where's your lion skin?" Jason interrupted.

"Jason," Kat snorted. Hercules looked more amused than annoyed.

"It's ninety degrees out here," he said. "Why would I wear my lion skin? Do you wear a fur coat to the beach?"

"I guess that makes sense." Jason sounded disappointed. "It's just that the pictures always show you with a lion skin."

Hercules glared at the sky accusingly, like he wanted to have words with his father, Lord Zeus. "Don't believe everything you hear about me. Being famous isn't as fun as you might think."

"Tell me about it," Piper sighed.

Hercules fixed his gaze on her. "Are you famous?"

"My dad . . . he's in the movies."

Hercules snarled. "Don't get me started with the movies. Gods of Olympus, they never get anything right. Have you seen one movie about me where I look like me?"

Piper nodded. "I'm surprised you're so young."

"Ha! Being immortal helps. But, yes, I wasn't so old when I died. Not by modern standards. I did a lot during my years as a hero . . . too much, really." His eyes drifted to Kat. "Well, well. Your line's still alive?"

"Surprisingly," answered Kat.

He let out a laugh at that. "Michael was a good friend of mine. Good fighter. A shame he died."

"Gee, thanks," Kat glanced at Jason, stifling something — a laugh, a scoff. She didn't know what, but it was something.

Hercules followed her gaze to Jason. "Son of Zeus, eh?"

"Jupiter," said Jason.

"Not much difference," grumbled Hercules. "Dad's annoying in either form. Me? I was called Heracles. Then the Romans came along and named me Hercules. I didn't really change that much, though lately just thinking about it gives me splitting headaches . . ."

The left side of his face twitched. His robes shimmered, momentarily turning white, then back to purple.

"At any rate," Hercules said, "if you're Jupiter's son, you might understand. It's a lot of pressure. Enough is never enough. Eventually it can make a guy snap."

He turned to Kat and Piper. Kat felt like a thousand ants were crawling up her back. There was a mixture of sadness and darkness in his eyes that seemed not quite sane, and definitely not safe. Is that how Kat usually looked? Yikes.

"As for you, my dears," Hercules said, "be careful. Sons of Zeus can be . . . well, never mind."

Yeah, well, I'll take my chances, Kat thought.

"So, Lord Hercules," Piper said, "we're on a quest. We'd like permission to pass into the Mediterranean."

Hercules shrugged. "That's why I'm here. After I died, Dad made me the doorkeeper of Olympus. I said, Great! Palace duty! Party all the time! What he didn't mention is that I'd be guarding the doors to the ancient lands, stuck on this island for the rest of eternity. Lots of fun."

He pointed at the pillars rising from the surf. "Stupid columns. Some people claim I created the whole Strait of Gibraltar by shoving mountains apart. Some people say the mountains are the pillars. What a bunch of Augean manure. The pillars are pillars."

"Riiiiiiiight," said Kat. "Naturally. So . . . can we pass?"

The god scratched his fashionable beard. "Well, I have to give you the standard warning about how dangerous the ancient lands are. Not just any demigod can survive the Mare Nostrum. Because of that, I have to give you a quest to complete. Prove your worth, blah, blah, blah. Honestly, I don't make a big deal of it. Usually I give demigods something simple like a shopping trip, singing a funny song, that sort of thing. After all those labors I had to complete for my evil cousin Eurystheus, well . . . I don't want to be that guy, you know?"

"Appreciate it," Jason said.

"Hey, no problem." Hercules sounded relaxed and easygoing, but something about him was lighting up Kat's fight or flight instinct. That dark glint in his eyes reminded her of charcoal soaked in kerosene, ready to go up at a moment's notice.

"So anyway," said Hercules, "what's your quest?"

"Giants," said Kat. "We're off to Greece to stop them from awakening Gaea."

"Giants," Hercules muttered. "I hate those guys. Back when I was a demigod hero, with your ancestor . . . ah, but never mind. So which god put you up to this — Dad? Athena? Maybe Aphrodite?" He raised an eyebrow at Piper. "As pretty as you are, I'm guessing that's your mom."

Kat should've been the hero here, but she hadn't realized what the dude had been talking about. Also, Jason and Piper were always the heroes in this situation. Why should she be the hero?

"Hera sent us," Jason said. "She brought us together to—"

"Hera." Suddenly Hercules's expression was like the cliffs of Gibraltar — a solid, unforgiving sheet of stone.

"We hate her too," Piper said quickly."We didn't want to help her. She didn't give us much choice, but—"

"But here you are," Hercules said, all friendliness gone. "Sorry, you three. I don't care how worthy your quest is. I don't do anything that Hera wants. Ever."

Jason looked mystified. "But I thought you made up with her when you became a god."

"Like I said," Hercules grumbled, "don't believe everything you hear. If you want to pass into the Mediterranean, I'm afraid I've got to give you an extra-hard quest."

"But we're like brothers," Jason protested. "Hera's messed with my life, too. I understand—"

"You understand nothing," Hercules said coldly. "My first family: dead. My life wasted on ridiculous quests. My second wife dead, after being tricked into poisoning me and leaving me to a painful demise. And my compensation? I got to become a minor god. Immortal, so I can never forget my pain. Stuck here as a gatekeeper, a doorman, a . . . a butler for the Olympians. No, you don't understand. The only god who understands me even a little bit is Dionysus. And at least he invented something useful. I have nothing to show except bad film adaptations of my life."

Piper turned on the charmspeak. "That's horribly sad, Lord Hercules. But please go easy on us. We're not bad people."

"Yeah," Kat added. "You don't think I know about how Michael died? He died because he'd gone insane, and look at where it got my family. Hundreds dying because they'd gone mad. The Mikhailov line almost being wiped out so many times. And yet we're still here, carrying on his legacy. Because he deserves to live on."

She thought they'd succeeded. Hercules hesitated. Then his jaw tightened, and he shook his head. "On the opposite side of this island, over those hills, you'll find a river. In the middle of that river lives the old god Achelous."

Hercules waited, as if this information should send them running in terror.

"And . . . ?" Kat asked.

"And," Hercules said, "I want you to break off his other horn and bring it to me."

"He has horns," Jason said. "Wait . . . his other horn? What—?"

"Figure it out," the god snapped. "Here, this should help."

He said the word help like it meant hurt. From under his robes, Hercules took a small book and tossed it to Piper. Kat sped up her arms and caught the book because she didn't want it to hit her girlfriend ( and because she wanted to show off ), immediately handing it to her.

"Bring me that horn by sundown," said Hercules. "Just the three of you. No contacting your friends. Your ship will remain where it is. If you succeed, you may pass into the Mediterranean."

"And if we don't?" Piper asked as if she wanted the answer.

"Well, Achelous will kill you, obviously," Hercules said. "And I will break your ship in half with my bare hands and send your friends to an early grave."

Jason shifted his feet. "Couldn't we just sing a funny song?"

"I'd get going," Hercules said coldly. "Sundown. Or your friends are dead."