BROOKLYN WASN'T SURPRISED when the snake people arrived.

By now, she's learned that shit just happens, and she's just along for the ride. So when the ship docked at the harbor in Piraeus, on the outskirts of Athens, Brooklyn fully expected something to happen. Sure, they had finally reached their destination. Somewhere nearby — past those rows of cruise ships that Piper restrained her from going to, past those hills crowded with buildings — they would find the Acropolis. Today, one way or another, their journey would end.

But that didn't mean she could relax. Any moment, shit might come flying out of nowhere.

As it turned out, the surprise was three dudes with snake tails instead of legs.

Piper and Brooklyn were on watch while the others geared up for combat — checking their weapons and armor, loading the ballistae and catapults. To be honest, though, Brooklyn and Piper were just talking about shit, not really watching out for stunning bad. But then Piper spotted the snake guys slithering along the docks, winding through crowds of mortal tourists who paid them no attention, and nudged Brooklyn and pointed at them.

"Babe?" Brooklyn called.

Annabeth and Percy came to her side.

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

Annabeth narrowed her eyes. "I don't think so. At least not like any I've seen. Dracaenae have two serpent trunks for legs. These guys just have one."

"You're right," Percy said. "These look more human on top, too. Not all scaly and green and stuff. So do we talk or fight?"

The snake man in the lead held his head high. His face was chiselled and bronze, his eyes black as basalt, his 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 guys behind him appeared to be guards. They wore 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. He might have been angry or worried or terribly in need of a restroom.

"Permission to come aboard." He said in a raspy voice.

"Who are you?" Brooklyn asked.

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."

Piper glanced at them. "A trick?"

"Probably," Annabeth said.

"At least he brought dessert." Brooklyn smiled down at the snake guys. "Welcome aboard!"

Kekrops agreed to leave his guards above deck with Buford the table, who ordered them to drop and give him twenty push-ups. The guards seemed to take this as a challenge.

Meanwhile, the king of Athens was invited to the mess hall for a 'get to know you' meeting.

"Please take a seat," Jason offered.

Kekrops wrinkled his nose. "Snake people do not sit."

"Please remain standing," Leo said. He cut the cake and stuffed a piece in his mouth.

"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," Kekrops said. "We are lactose-intolerant reptiles."

"Me, too!" Frank said. "I mean . . . lactose intolerant. Not a reptile. Though I can be a reptile sometimes—"

"Anyway," Hazel interrupted, "King Kekrops, what brings you here? How did you know we'd arrived?"

"I know everything that happens in Athens," Kekrops 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," Percy muttered.

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."

"Like your zodiac sign?" Percy asked. "I'm a Leo."

"No, stupid," Leo said. "I'm a Leo. You're a Percy."

"Will you two stop it?" Hazel chided. "I think he means gemini like doubled — half man, half snake. That's what his people are called. He's a geminus, singular."

"Yes . . ." Kekrops leaned away from Hazel as if she somehow offended him. "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. "The Acropolis is ringed with great siege weapons — onagers."

"More onagers?" Frank protested. "Did they have a sale on them or something?"

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

Brooklyn snorted. "Like we needed more proof that Octavian is on the wrong side."

"That is not the only threat," Kekrops warned. "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."

"What's the catch?" Piper asked.

Kekrops turned to her. "Only a small party of demigods — no more than three — 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?" Leo asked. "Oh . . . like, to wake Gaia."

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

Brooklyn heard eagerness in his voice — almost hunger.

Percy looked around the table. "Any objections?"

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

"Yup," Brooklyn stuffed cake in her mouth.

"Also," Percy said, "Gaia 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?"

Naturally, Piper began to sing. Because there obviously was no other answer she could give.

Kekrops stared at her in wonder. He began to sway.

Her words filled the mess hall. Everyone listened, transfixed.

She finished the first verse. No one spoke for a count of five.

"Pipes," Jason said, "I had no idea."

"That was beautiful," Leo agreed. "Maybe not . . . you know, Calypso beautiful, but still . . ."

Piper kept her gaze on the snake. "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."

"Why?" asked Piper.

"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," said Piper. "You founded her city."

The snake 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 Gaia. The Earth Mother has promised us a place in the sun of the upper world."

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

The snake 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.

The snake'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 Acropolis — 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," Piper said. "That's also true?"

Kekrops frowned. "Yes . . ."

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

"Yes, but . . ." The snake shuddered. "Yes, they would obey. Three 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 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," Hazel said, "if it's underground."

"Never," Kekrops said. "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."

"Me and Percy," Annabeth suggested.

"Um . . ." Percy raised his hand. "Just gonna throw this out here again. That's exactly what Gaia 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 admitted. "Your . . . your scent would be difficult to discern. The ruins always radiate the power of those two gods."

"And me," Piper said at the end of her song. "You'll need me to keep our friend here in line."

Jason squeezed her hand. "I still hate the idea of splitting up."

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

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

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

Piper started a different song. Annabeth, Leo, Frank and Hazel left to talk strategy.

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