They docked in Piraeus.

Emilia had polished Incubo while praying a rosary. She'd considered Iris-messaging her aunt, her siblings, and Pollux, but feared that it would make her dread what was to come. They'd be alright. She thought of them each fondly, she tried to imagine them waiting for her to return.

Beneath her armor, she wore her necklace from Camp Half-Blood, as a reminder of where she'd begun this new chapter of her life. She layered over it her necklace with the apple of discord, to remind her of her family on both sides.

Once she was ready, she went up to the deck, joining Piper in gazing over the docks, the outskirts of Athens. It didn't make her feel happy knowing they'd reached their destination– this was only the beginning of the end. Somewhere nearby– past those rows of cruise ships and hills crowded with buildings– they would find the Acropolis filled with monsters ready to skewer them.

"Uh..." Piper pointed ahead. "What the hell are those?"

Emilia turned after having been observing how Frank loaded the ballistae and catapults. Three men with snake tails instead of legs slithered along the docks, winding through crowds of mortal tourists who paid them no attention."

"Oh, great," said Percy. "Dracaenae."

"Nope," said Emilia uncomfortably. "Made the same mistake once and Atlas corrected me... those are gemini."

"Like the zodiac sign?" said Percy. "I'm a Leo."

"No, stupid," said Leo from the control panel. "I'm a Leo. You're a Percy."

"It means half man and half snake," said Emilia, who didn't know her own zodiac sign. "Dracaenae are different, they have two serpent trunks and don't look this... human on top."

Percy cringed. "So do we talk or fight?"

"Fight," said Emilia. "The gemini are as two-faced as they are two-bodied."

She watched the geminus in the lead, his head held high, face chiseled and bronze, eyes black as basalt, curly dark hair glistening with oil. His upper body rippled with muscles, covered only by a Greek chlamys– a white wool cloak loosely wrapped and pinned at the shoulder. From the waist down, his body was one giant serpent trunk– about eight feet of green tail undulating behind him as he moved.

In one hand he carried a staff topped with a glowing green jewel. In his other, he carried a platter covered with a silver dome, like a main course for a fancy dinner. The two behind them appeared to be guards, donning bronze breastplates and elaborate helmets topped with horsehair bristles. Their spears were tipped with green stone points. Their oval shields were emblazoned with a large Greek letter K– kappa.

They stopped a few yards from the Argo II. The leader looked up and studied the demigods. His expression was intense but inscrutable. "Permission to come aboard," he rasped.

"Who are you?" asked Piper calmly, much more patiently than Emilia would have mustered.

He fixed his dark eyes on her. "I am Kekrops, the first and eternal king of Athens. I would welcome you to my city." He held up the covered platter. "Also, I brought a Bundt cake."

Emilia couldn't really bring herself to say no to Bundt cake, but she refused to eat something that was brought so suspiciously. She still preferred to just leap off the boat and cut the snake men to ribbons.

Piper glanced at the others. "A trick?"

"Undoubtedly," muttered Emilia. "We can take them."

"At least he brought dessert," said Percy. He smiled down at the snake guys, always the cooperative one. "Welcome aboard!"

Only the king of Athens was allowed in the mess hall, the guards supervised above deck by Buford, who demanded they give twenty push-ups. Leo almost immediately dug into the Bundt cake without worrying if it was poisoned or not.

"Dang!" He grinned. "Snake people know how to make Bundt cake. Kind of orangey, with a hint of honey. Needs a glass of milk."

"Snake people do not drink milk," said Kekrops. "We are lactose-intolerant reptiles."

"Me, too!" said Frank. He blushed. "I mean... lactose intolerant. Not a reptile."

Hazel changed the subject as Frank got a piece for himself, figuring he'd be fine if Leo hadn't already doubled over. "King Kekrops, what brings you here? How did you know we'd arrived?"

"I know everything that happens in Athens," he said. "I was the city's founder, its first king, born of the earth. I am the one who judged the dispute between Athena and Poseidon, and chose Athena to be the patron of the city."

"No hard feelings, though," muttered Percy.

Annabeth elbowed him. "I've heard of you, Kekrops. You were the first to offer sacrifices to Athena. You built her first shrine on the Acropolis."

"Correct." Kekrops sounded bitter, like he regretted his decision. "My people were the original Athenians– the gemini. Millennia ago, we were driven underground by the two-legged humans, but I know the ways of the city better than any. I came to warn you. If you try to approach the Acropolis aboveground, you will be destroyed."

Jason stopped nibbling his cake. "You mean... by you?"

"By Porphyrion's armies," said the snake king. "The Acropolis is ringed with great siege weapons– onagers."

"More onagers?" protested Frank.

"The Cyclopes," guessed Hazel. "They're supplying both Octavian and the giants."

Percy grunted. "Like we needed more proof that Octavian is on the wrong side."

"That is not the only threat," warned Kekrops. "The air is filled with storm spirits and gryphons. All roads to the Acropolis are patrolled by the Earthborn."

Frank drummed his fingers on the Bundt cake cover. "So, what, we should just give up? We've come too far for that."

"I offer you an alternative," said Kekrops. "Underground passage to the Acropolis. For the sake of Athena, for the sake of the gods, I will help you."

Emilia glanced at Piper, the two of them seemingly in agreement that something about this sounded too good to be true. Emilia would rather err on the side of caution.

Piper posed, "What's the catch?"

Kekrops turned those inscrutable dark eyes on her. "Only a small party of demigods– no more than four– could pass undetected by the giants. Otherwise your scent would give you away. But our underground passages could lead you straight into the ruins of the Acropolis. Once there, you could disable the siege weapons by stealth and allow the rest of your crew to approach. With luck, you could take the giants by surprise. You might be able to disrupt their ceremony."

"Ceremony?" asked Leo. "Oh... like, to wake Gaea."

"Even now it has begun," warned Kekrops. "Can you not feel the earth trembling? We, the gemini, are your best chance."

Percy looked around the table. "Any objections?"

"Just a few," said Jason. "We're on the enemy's doorstep. We're being asked to split up. Isn't that how people get killed in horror movies?"

"Also," said Percy, "Gaea wants us to reach the Parthenon. She wants our blood to water the stones and all that other psycho garbage. Won't we be playing right into her hands?"

"I have a bad feeling about this, too," said Emilia, glancing at Annabeth, then at Piper.

It surprised her when Piper's response was to start singing. A mesmerizing little tune, some song called 'Summertime.' Kekrops stared at Piper in wonder, then began to sway. The others didn't dare move a muscle, both to give Piper her space to do whatever she was trying to do, and also to be on guard because they had no idea what was going to happen next.

As she finished the first verse, it went silent. After a count of five, Jason said, "Pipes, I had no idea."

"That was beautiful," agreed Leo.

Piper kept the snake king's gaze. "What are your real intentions?"

"To deceive you," he said in a trance, still swaying. "We hope to lead you into the tunnels and destroy you."

"And there it is," muttered Emilia under her breath.

"Why?" Piper asked Kekrops.

"The Earth Mother has promised us great rewards. If we spill your blood under the Parthenon, that will be sufficient to complete her awakening."

"But you serve Athena. You founded her city."

Kekrops made a low hiss. "And in return the goddess abandoned me. Athena replaced me with a two-legged human king. She drove my daughters mad. They leaped to their deaths from the cliffs of the Acropolis. The original Athenians, the gemini, were driven underground and forgotten. Athena, the goddess of wisdom, turned her back on us, but wisdom comes from the earth as well. We are, first and last, the children of Gaea. The Earth Mother has promised us a place in the sun of the upper world."

"Gaea is lying," said Piper. "She intends to destroy the upper world, not give it to anyone."

Kekrops bared his fangs. "Then we will be no worse off than we were under the treacherous gods!" He raised his staff, but Piper launched into another verse of 'Summertime.' The snake king's arms went limp. His eyes glassed over. Piper sang a few more lines, then she risked another question: "The giants' defenses, the underground passage to the Acropoli – how much of what you told us is true?"

"All of it," said Kekrops. "The Acropolis is heavily defended, just as I described. Any approach aboveground would be impossible."

"So you could guide us through your tunnels," said Piper. "That's also true?"

Kekrops frowned. "Yes..."

"And if you ordered your people not to attack us, they would obey?"

"Yes, but..." Kekrops shuddered. "Yes, they would obey. Four of you at most could go without attracting the attention of the giants."

Annabeth's eyes darkened. "Piper, we'd be crazy to try it. He'll kill us at the first opportunity."

"Yes," the snake king agreed. "Only this girl's music controls me. I hate it. Please, sing some more."

Piper gave him another verse. Leo got into the act. He picked up a couple of spoons and made them do high kicks on the tabletop until Hazel slapped his arm.

"I should go," said Hazel, "if it's underground."

"Never," said Kekrops. "A child of the Underworld? My people would find your presence revolting. No charming music would keep them from slaying you."

Hazel swallowed. "Or I could stay here."

"I could go," offered Emilia. "I may be a child of the Underworld– further than that, even– but my mother taught me to hide in darkness and the monsters will sense more monsters with my presence, not anything demigod-like. The geminiwouldn't need to see me at all. It could give us an advantage against whatever we encounter down there if they don't realize I'm there. Besides, there is no way I'm going to sit here waiting now that we're here. The battle is coming and my mother promised to be there when I needed her most. If I need to call to her, to beg her to make that final jump over the River Acheron, I have to be present to make it happen."

Kekrops didn't seem to like it, but he couldn't appear to find an argument against that which his people wouldn't be able to see. "Good," said Emilia. "So me and Piper so far. Who else?"

"Me and Percy," suggested Annabeth.

"Um..." Percy raised his hand. "Just gonna throw this out here again. That's exactly what Gaea wants– you and me, our blood watering the stones, et cetera."

"I know." Annabeth's expression was grim. "But it's the most logical choice. The oldest shrines on the Acropolis are dedicated to Poseidon and Athena. Kekrops, wouldn't that mask our approach?"

"Yes," the snake king admitted. "Your... your scent would be difficult to discern. The ruins always radiate the power of those two gods."

Jason squeezed Piper's hand. "I just... hate the idea of splitting up."

"But it's our best shot," said Frank. "The four of them sneak in and disable the onagers, cause a distraction. Then the rest of us fly in with ballistae blazing."

"Yes," said Kekrops. "That plan could work. If I do not kill you first."

"I've got an idea," said Annabeth. "Frank, Hazel, Leo... let's talk. Piper, can you keep our friend musically incapacitated?'

Piper started a different song: 'Happy Trails,' while the others went to talk strategy. Emilia waited at the table, drumming her fingers against it as rhythmically as she could and trying to imagine her mother was ready, that she'd faced her demons and would be able to enter this world to help them defeat the giants. And if not... well, Emilia was going to have to cause one hell of a distraction on her own.

"Well." Percy rose and offered his hand to Jason. "Until we meet again at the Acropolis, bro. I'll be the one killing giants."

-

It was weird to walk alongside them without being visible, but Emilia tried to treat it as a game.

From the port to the Acropolis, there was nothing to see in Athens except dark, putrid tunnels. The snake men led them through an iron storm grate at the docks, straight into their underground lair, which smelled of rotting fish, mold, and snakeskin.

There was a plethora of shadows to draw from, just enough to make her invisible while in constant motion. She could walk and the darkness would simply latch onto her, making her part of the shadows and bouncing light around to feed the illusion of her absence.

Piper was brave enough to keep singing. If she stopped for longer than a minute or two, Kekrops and his guards started hissing and looking angry. Emilia would've held her hand for comfort if she could guarantee it wouldn't scare the shit out of Piper. Both of them were watching Annabeth and Percy holding hands, the underground reminding Annabeth of her terrible quest in Rome.

The others tried to remain quiet so as to let Piper's voice echo through the tunnels. As they traveled further into the lair, more snake people gathered to hear her. Soon they had a procession following behind them– dozens of gemini all swaying and slithering. Emilia had to walk extra fast to keep them from realizing she was there.

They passed through crude stone chambers littered with bones. They climbed slopes so steep and slippery it was nearly impossible to keep their footing– Emilia had had to move the shadows as best as she could to give the others a better grip on their feet. At one point, they passed a warm cave the size of a gymnasium filled with snake eggs, their tops covered with a layer of silver filaments like slimy Christmas tinsel.

More and more snake people joined their procession. Slithering behind her, they sounded like an army of football players shuffling with sandpaper on their cleats. It wasn't the worst of the noises down there– a perceptible heartbeat echoed through the corridors, getting louder and louder the deeper they went.

It resonated through the stone and air, along with a voice that hissed, I wake, as clear as Piper's singing.

Annabeth froze. "Oh, that's not good."

"It's like Tartarus," said Percy, voice edgy. "You remember... his heartbeat. When he appeared–"

"Don't," pleaded Annabeth. "Just don't."

"Sorry."

The voice of Gaea spoke again, louder: At last.

Piper's singing wavered. Emilia risked placing a hand on her shoulder, which at first made Piper flinch until she realized what it was.

Finally they reached the top of a steep slope, where the path ended in a curtain of green goo. Kekrops faced the demigods. "Beyond this camouflage is the Acropolis. You must remain here. I will check that your way is clear."

"Wait." Piper turned to address the crowd of gemini. "There is only death above. You will be safer in the tunnels. Hurry back. Forget you saw us. Protect yourselves." The fear in her voice channeled perfectly with the charmspeak. The snake people, even the guards, turned and slithered into the darkness, leaving only the king. "Kekrops, you're planning to betray us as soon as you step through that goo."

"Yes," he agreed. "I will alert the giants. They will destroy you." Then he hissed. "Why did I tell you that?"

"Listen to the heartbeat of Gaea," urged Piper. "You can sense her rage, can't you?"

Kekrops wavered. The end of his staff glowed dimly. "I can, yes. She is angry."

"She'll destroy everything. She'll reduce the Acropolis to a smoking crater. Athens– your city– will be utterly destroyed, your people along with it. You believe me, don't you?"

"I–I do."

"Whatever hatred you have for humans, for demigods, for Athena, we are the only chance to stop Gaea. So you will not betray us. For your own sake, and your people, you will scout the territory and make sure the way is clear. You will say nothing to the giants. Then you will return."

"That is... what I'll do." Kekrops disappeared through the membrane of goo.

"You are scarily impressive, Piper," whispered Emilia.

Annabeth nodded in agreement and amazement. "Piper, that was incredible."

"We'll see if it works." Piper sat down on the cool stone floor. Emilia joined her, allowing herself to be visible now that the gemini were gone. Percy handed Piper a canteen of water for her dry throat.

"You think the charm will last?" asked Percy.

"I'm not sure,' she admitted. "If Kekrops comes back in two minutes with an army of giants, then no."

The heartbeat of Gaea echoed through the floor. Piper held Emilia's hand, and maybe, just maybe, it managed to make her feel less afraid.

At last, at the top of the tunnel, the green membrane rippled. They all rose, weapons drawn, prepared for a flood of monsters. Instead, Kekrops emerged alone.

"The way is clear," he said. "But hurry. The ceremony is almost complete."

They had to trudge through the disgusting curtain of mucus, which was about as gross as they'd imagined. They found themselves in a cool, damp pit that seemed to be the basement level of a temple. All around them, uneven ground stretched into darkness under a low ceiling of stone. Directly above their heads, a rectangular gap was open to the sky. They could see the edges of walls and the tops of columns, but no monsters... yet.

The camouflage membrane had closed behind them and blended into the ground. Piper pressed her hand against it. The area seemed to be solid rock. They wouldn't be leaving the way they'd come.

Annabeth ran her hand along some marks on the ground – a jagged crow's-foot shape as long as a human body. The area was lumpy and white, like stone scar tissue. "This is the place," she said. "Percy, these are the trident marks of Poseidon."

Hesitantly, Percy touched the scars. "He must've been using his extra-extra-large trident."

"This is where he struck the earth," said Annabeth. "Where he made a saltwater spring appear when he had the contest with my mom to sponsor Athens."

"So this is where the rivalry started," said Percy.

"Yeah..."

Percy pulled Annabeth close and kissed her... long enough for it to get really awkward for Piper and Emilia, though they said nothing. Emilia knew how important this moment was for them, how much they'd had to deal with because of that rivalry. It made her heart ache as she thought of Hylla, both of them unaware of what the other was currently facing.

When Percy pulled away, Annabeth looked like a fish gasping for air. "The rivalry ends here," said Percy. "I love you, Wise Girl." Annabeth made a little sigh, like something in her ribcage had melted. Percy glanced at the others. "Sorry, I had to do that."

Piper grinned. "How could a daughter of Aphrodite not approve? You're a great boyfriend."

"Exactly," said Emilia. "You two may be younger than me but you were like parents who welcomed me to camp, so... can't judge."

Annabeth made another grunt-whimper, still a bit flustered. "Uh... anyway. We're beneath the Erechtheion. It's a temple to both Athena and Poseidon. The Parthenon should be diagonally to the southeast of here. We'll need to sneak around the perimeter and disable as many siege weapons as we can, make an approach path for the Argo II."

"It's broad daylight," said Piper. "How will we go unnoticed?'

Annabeth scanned the sky. '"That's why I made a plan with Frank and Hazel. Hopefully... ah. Look." A bee zipped overhead. Dozens more followed. They swarmed around a column, then hovered over the opening of the pit. "Say hi to Frank, everybody."

"I have so many questions," said Emilia quietly, which Percy nodded to.

"He's our go-between," said Annabeth. "As soon as he gives Hazel the word, she will–"

Percy yelped. Annabeth clamped her hand over his mouth, the two of them suddenly resembling hulking, six-armed Earthborn. She and Piper now had Neanderthal bodies– belly hair, loincloth, stubby legs and oversized feet. It was difficult for Emilia make out her real body beneath the Mist, all she could really see were her three different sets of muscular Earthborn arms.

"Hazel's Mist," said Piper, her voice deep and gravelly.

Percy grimaced, which looked even worse on his newly uglified face. "Wow, Annabeth... I'm really glad I kissed you before you changed."

"Thanks a lot," she said. "We should get going. I'll move clockwise around the perimeter. Piper, you move counterclockwise. Percy, Emilia, you scout the middle–"

"Wait," said Percy. "We're walking right into the whole blood-spilling sacrifice trap we've been warned about, and you want to split up even more?"

"We'll cover more ground that way," said Annabeth. "We have to hurry. That chanting..."

It sounded like an ominous drone in the distance. Bits of gravel trembled on the ground, skittering southeast, as if pulled towards the Parthenon.

"Rendezvous at the giant's throne," said Emilia. "Good luck, everyone."

Mother, please don't abandon me.