TWENTY FOUR.     where the sun meets the sea

Honestly, Theo thought she was dead. She thought she had died and Heaven was just really intense when you first got there. It didn't occur to her that Greek gods didn't observe Heaven, or anything—just that she was facing some sort of Day of Reckoning, or something.

As the roof of the cavern collapsed, sunlight blinded her. She got the briefest glimpse of the Argo II hovering above. It must have used its ballistae to blast a hole straight through the ground. Chunks of asphalt as big as houses tumbled down, along with six or seven cars and a Vespa. One would've crushed the Apollo Belvedere, but the statue's glowing aura acted like a force field, and the car bounced off. Unfortunately, it fell straight toward Theo.

She jumped to one side, twisting her bad foot. A wave of agony almost made her pass out, but she flipped on her back in time to see a bright red Fiat slam into Python's self-induced trap, punching through the cavern floor and disappearing with the Bavarian pretzel.

As he fell, Python roared like a freight train on a collision course; but his screeches rapidly faded. All around Theo, more chunks of debris slammed through the floor, riddling it with holes. She ducked and weaved, rolling through miles of snakeskin and the leftover snapped arrows from her trick to defeating Python. One lodged itself in her elbow; she choked back a scream.

The army of snakes, thankfully, had disappeared. Either they'd fled back the way they'd came, or they'd fallen into the chasm.  As daylight flooded the chamber, Theo blinked back tears, ferocious waves of relief, fear, pain, and despair overcoming her all at once.

But none of that mattered when she heard Percy's voice from above. "Theo!"

"Here!" she sobbed, collapsing onto her side.

All the negative emotions seemed to leave her in one tiny breath. As the Argo II descended, she saw Percy leaning over the rail. His smile was better than anything she had ever seen, and relief flooded her senses like a tsunami.

The room kept shaking, and Theo stayed down, squeezing her eyes shut. The floor beneath her seemed stable for the moment. Her backpack was missing, along with everything in it. Her dagger, which she'd had since she was a kid, was also gone—probably fallen into the pit. But Theo didn't care. She was alive, and she had her father's bow.

She edged closer to the gaping hole made by the stray car. Jagged rock walls plunged into the darkness as far as Theo could see. A few small ledges jutted out here and there, but Theo saw nothing on them—just coils of snakeskin dripping over the sides like Christmas tinsel.

Theo wondered if Python's implications about the destination of this pit held true. Had he really just fallen all the way to Tartarus? The things Theo had heard of the place, she almost thought it was too harsh an end, even for Python...

She was dimly aware of the Argo II hovering to a stop about forty feet from the floor. It lowered a rope ladder, but Theo stood in a daze, staring into the darkness. Then suddenly Percy was next to her, lacing his fingers in hers.

He turned her gently away from the pit and wrapped his arms around her. She buried her face in his chest and broke down in tears.

"It's okay," he said. "I've got you."

Theo exhaled a shaky sob. That was all she needed to hear. After all they'd been through over the last year, he knew the most important thing was that they were back together.

Their friends gathered around them. Nico di Angelo was there, but Theo's thoughts were so fuzzy, this didn't seem interesting to her. It seemed only right that he would be with them. She held out a hand to him, and he accepted a little side hug, which Theo dimly registered as something that should have been surprising.

"Your foot." Hazel knelt next to her and examined the horrid scene that was Theo's injury. "Oh, gods, what happened?"

She started to explain. Talking was difficult, but as she went along, her words came more easily. Percy didn't let go of her hand, which also made her feel more confident. When she finished, her friends' faces were slack with amazement.

"Gods of Olympus," Jason said. "You did all that alone. With a broken foot."

"Well... some of it with a broken foot."

Percy grinned. "You outsmarted Python 'Jungle Book' style. I knew you were good, but Holy Hera—Theo, you did it. Generations of Apollo kids tried and failed. You found the statue."

Everyone gazed at the Apollo Belvedere.

"I still have to destroy it," Theo noted quietly, appraising the statue like she was an artist. "But once it's gone... Centuries of resentment between Greeks and Romans will be erased. It will help us stop Gaea, defeat the giants."

"Darkness' bane stands marble and pale," Hazel quoted. "Won through brevity at serpent's fail." She looked at Theo with admiration. "It was Python's fail. You tricked him into defeat."

Theo smiled, but she didn't feel very happy on the inside. Something still felt wrong. Maybe it was her broken foot.

Leo raised his hands. He made a finger picture frame around the Apollo Belvedere like he was taking measurements. "Well, it might take some rearranging, but I think we can fit him through the bay doors in the stable. If he sticks out the end, I might have to wrap a flag around his feet or something."

Theo wet her lips, eyeing the statue, suspicious. Maybe she should just destroy it here, let it die where it had been all along...

Then she thought about the other lines of the prophecy: The twins snuff out the angel's breath, who holds the keys to endless death.

"What about you guys?" she asked. "What happened with the giants?"

Percy told her about rescuing Nico, the help of Athena, and the fight with the twins beneath the Colosseum. Nico didn't say much. The poor guy looked like he'd been wandering through a wasteland for six weeks. Percy explained what Nico had found out about the Doors of Death, and how they had to be closed on both sides. Even with sunlight streaming in from above, Percy's news made the cavern seem dark again.

"So the mortal side is in Greece," Theo said. "At least that's somewhere we can... reach, I guess."

Nico grimaced. "But the other side is the problem. Tartarus."

The word seemed to echo through the chamber. The pit behind them exhaled a cold blast of air. That's when Theo knew with certainty. The chasm did go straight to the Underworld.

Percy must have felt it too. He guided her a little farther from the edge. Her arms and legs trailed shedded snakeskin like a bridal train, which she thought was funny; almost like she was getting married to Percy in the most perverse place possible. She almost mentioned something about it.

Then Mayfair spoke up. "In my vision, Bacchus mentioned something about Percy's voyage being harder than we all expect. Not sure why—"

The chamber groaned. The Apollo Belvedere listed to one side. Its head caught on one of the edges of the cavern, but the marble foundation beneath the statue was crumbling.

"Secure it," Theo said at once. She wasn't sure why letting the statue fall into Tartarus was the wrong move here, but it was, and somehow she knew it for a fact. She had to be the one to destroy it. Not nature. Not anything else. A child of Apollo.

Her friends understood immediately.

"Zhang!" Leo cried. "Get me to the helm, quick! The coach is up there alone."

Frank transformed into a giant eagle, and the two of them soared toward the ship.

Jason wrapped his arm around Mayfair, then turned to Percy. "Back for you guys in a sec." He summoned the wind and shot into the air, blond Peter Pan back at it again.

"This floor won't last!" Hazel warned, and Theo trusted her judgement, due to the undergroundness of it all. "The rest of us should get to the ladder."

Plumes of dust and cobwebs blasted from holes in the floor. Hazel lunged for the bottom of the rope ladder and gestured for Nico to follow, but he was in no condition to sprint.

Percy gripped Theo's hand tighter. "It'll be fine," he muttered.

She swallowed. "You think?"

"I know."

Looking up, she saw grappling lines shoot from the Argo II and wrap around the statue. One lassoed Apollo's neck like a noose. Theo almost laughed. Leo shouted orders from the helm as Jason and Frank flew frantically from line to line, trying to secure them.

Nico had just reached the ladder when a sharp pain shot up Theo's bad leg. She gasped and stumbled back a step, her chin hitting her chest.

"What is it?" Percy asked, spreading his hands in sensitivity like he'd been the one to hurt her.

She tried to list toward the rope ladder. Why was she moving backward instead? Was it Opposite Day? Her legs swept out from under her and she fell flat on her face; she felt a horrible cracking sensation in her nose, then warmth spread down her chin. Blood trailed on the stone beneath her.

"Her ankle!" Mayfair screamed from the deck, looking absolutely manic. She waved her hands in the air, but nobody was having any issues seeing her. "Cut it! Cut it!"

Theo's mind was woozy from the pain and exhaustion. Cut her ankle? What the hell was this girl on about?

Apparently Percy didn't realize what Mayfair meant either. Then something yanked Theo backward and dragged her toward the pit, a bright red trail of blood beneath her wake. Percy lunged. He grabbed her arm, fingers digging into her skin, but the momentum carried him along as well.

"Help them!" Hazel screamed.

Theo glimpsed Nico hobbling in their direction, Hazel trying to disentangle her cavalry sword from the rope ladder. Mayfair couldn't get down the ladder with Hazel in the way. Their other friends were still focused on the statue, and Hazel's cry was lost in the general shouting and the rumbling of the cavern. Theo could just make out Leo still shouting directions at Frank and Jason.

Theo gasped as she hit the edge of the pit, air knocked flat from her lungs. Her legs went over the side. Too late, she realized what was happening: she was tangled beyond hope in the miles of snakeskin. She should have cut it off immediately, freed herself from the coil. She had thought it was just loose strand, but with the entire floor covered in skin, she hadn't noticed that it was wrapped around her foot—and the other end went straight into the pit. It was attached to something heavy down in the darkness, something that was pulling her in. Something that didn't feel like an accident.

"No," Percy muttered, light dawning in his eyes. "My sword..."

But he couldn't reach Riptide without letting go of Theo's arm, and Theo's strength was gone. She slipped over the edge. Percy tumbled down with her.

Her body slammed into something. She must have blacked out briefly from the pain. When she could see again, she realized that she'd fallen partway into the pit and was dangling over the void. Her vision was spotty and she didn't know if it was from fear or pain. Percy had managed to grab a ledge about fifteen feet below the top of the chasm. He was holding on with one hand, gripping Theo's wrist with the other, but the pull on her leg was much too strong. And she was in so much pain.

No escape, said a voice in the darkness below. I go to Tartarusssss, and you will come too.

Theo wasn't sure if she actually heard Python's voice or if it was just in her mind.

The pit shook like a black hole. Theo had felt this before, only once. Now Percy was the only thing keeping her from falling. He was barely holding on to a ledge the size of a bookshelf.

Nico leaned over the edge of the chasm, thrusting out his weak hand, but he was much too far away to help. Hazel was yelling for the others, but even if they heard her over all the chaos, they'd never make it in time.

Theo's leg felt like it was pulling free of her body. Pain washed everything in red. A guttural scream burst its way from her chest. The force of the Underworld tugged at her like dark gravity, like it had known all along she would end up inside. She didn't have the strength to fight. She knew she was too far gone to be saved.

"Percy, let me go," gasped Theo. "You can't hold me any longer."

Her shaking voice was cut off by a crumbling of the ledge supporting Percy's grip. His face was white with effort. She could see in his eyes that he knew it was hopeless.

"I'm never saying goodbye to you again," he said. He looked up at Nico, fifteen feet above. "The other side, Nico! We'll see you there. Understand?"

Nico's eyes widened. "But—"

"Lead them there!" Percy shouted. "Promise me!"

His gaze swam with something shiny. "I—I will."

Below them, a new voice laughed in the darkness. Sacrifices. Beautiful sacrifices to wake the earth.

Percy tightened his grip on Theo's wrist. His face was gaunt, scraped and bloody, his hair dusted with snakeskin and dust, but when he locked eyes with her, she thought he had never looked more godly.

"We're staying together," he promised. "You're not getting away from me again. I'm never letting you go, Theo."

Only then did she understand what would happen. A one-way trip at the end of a very hard fall. Theo should have known by then—prophecies were inescapable.

"As long as we're together," she whispered. She squeezed her eyes shut for a moment. "Goodbye, real world."

She heard Nico and Hazel still screaming for help. She saw the sunlight far, far above—maybe the last sunlight she would ever see. Ironic how that was what had gotten her into the mess, anyway, and now it was the only thing left to bid her farewell.

"Goodbye, real world," Percy agreed in a whisper, and the childishness of the phrase struck Theo like a fever pitch.

Funny, isn't it, how earlier Theo had tried so hard to snuff out the light in this cavern, and now she was the one being snuffed? Actions and their consequences, she realized. She was the action, and Percy, her consequence.

Green eyes met hazel, the sun met the sea, and all at once, Percy let go of his tiny ledge. Together, arms wrapped around each other like lifelines, he and Theo fell into the endless darkness.