He didn't look like Luke had, or Marcus or Titan. They'd had an indiscernible quality about them that made it obvious they were just apparitions. Nico, on the other hand, looked completely corporeal and as he had in life, but he wasn't alive.

"You're dead," said Percy. "Luke killed you. Marcus told me."

Nico flinched. "Yeah," he said, his voice and tone sounded exactly like the real Nico's. "I got hurt pretty bad, but Marcus never saw me or Bianca die. I was able to shadow-travel us away. Bianca —" he choked back a sob. "She didn't make it. But the Fates found me before I bled out and healed me. They saved me, Percy. And now I'm here to guide you through the Hollow."

Percy retreated a step back and his eyes widened. "You're. . . really you?"

He nodded. "It's me."

Nico touched the wall and the shadows visibly danced around his fingertips. Percy lowered his sword, but was still skeptical.

"It's not possible," he said. "You died."

Nico rolled his eyes. "You trust the word of a two-timing snake like Marcus over your cousin? Come on, you can see me. I'm really here, Percy."

"But why? Why would the Fates save your life just to put you in this place?"

"To guide you. The maze is —"

"They created it!" Percy yelled, but the irritation wasn't directed at him. "They created the Hollow. There's no point to any of this. There doesn't need to be a maze! Just let us through!"

Nico waited patiently for him to finish. "The Hollow's defenses are lethal to the unworthy, but valuable to the destined."

Percy stared at him. "What does that mean?"

"There is a purpose to this. You may not see it now, but the Hollow isn't trying to fight you off. The Fates want you here because your destiny is prophesied. Not just with this quest, but your life afterward. It's helping you shape yourself for the things to come."

"Even the automaton?"

"Well, that one was just to keep out basic intruders. Everything else is here to help you."

Percy eyed him for a few seconds then decided something. "You're not Nico."

Nico blinked. "Yes I am."

Percy shook his head. "No. You don't talk like him. You don't act like him. Nico really did die, and you're just another one of the Hollow's mirages."

"Astute, but you're wrong. I suppose you don't need to accept that yet for me to guide you, though."

"Where are Reyna and Jason?"

"In other mazes. They'll have their own guides, and will meet us outside. If you'd rather we not dawdle any longer, we might not be late in seeing them."

"Fine. Let's go."

Nico took the lead. He walked back the way Percy had come from and made the same turns before veering off to a new path. For several minutes they walked through the maze without anything interesting happening. Then Nico informed him that they were getting close — that's when the maze turned hostile.

A couple of metal spheres popped out from the walls and sat there for a second. Then, they transformed into human-sized versions of the automaton they'd faced at the start. Percy immediately jumped in to fight them, but unlike their big brother, they weren't much of a challenge. He swiftly destroyed them, while Nico did nothing.

"If you were actually him," Percy said, "you would've fought."

"I'm unarmed," Nico defended. "What would you expect me to do?"

"Anything but just stand there." Percy leaned down and picked up one of the robots' daggers, then handed it to his fake cousin.

The next time they ran into more machines, Nico fought. The real him didn't usually use daggers in combat, as he preferred a sword, but he was proficient enough. His fighting style was so spot on that for just a moment, Percy actually began to doubt how sure he was that this wasn't the real Nico.

But then he returned to sanity. "Nico" had clearly told him the Hollow was screwing with him to shape him into whatever the Fates had decided he was destined to be. He wasn't going to let that happen. After Nico and Bianca went missing, he'd spent so long wanting to know whether they were alive or dead before he finally accepted that they were gone. It had been hard enough to accept it then, but easier to bear than having Marcus confirm that they'd been killed. He wasn't going to convince himself Nico was alive just to have that hope ripped away yet again.

They proceeded onward. They faced some more automatons along the way, which were getting progressively more difficult the farther along they advanced. Eventually, the maze began trying to kill them in other ways. Nico stopped him from tripping over a wire that would have likely activated some deadly mechanism. With his help, they avoided all the traps, defeated the rest of the enemies, and finally reached the exit, except there was still one last obstacle.

They turned a final corner into a long hallway which he could barely see opened out into a cavern — hopefully not the same one as before. The issue was, a large lioness lay directly in their path, except she had the head of a woman that eyed them hungrily.

Percy held his sword at the ready and approached cautiously behind Nico. As soon as they were in range, she opened her mouth and spoke.

"What is the creature that walks on four legs in the —?" she started.

"Man," Percy interrupted.

Her eyes narrowed. "You didn't even let me finish."

"I already heard it before. The answer is 'man'."

"Then how about a different riddle?" she said in a deadly tone.

"Oh, no, you don't have to —"

"What is a creature so impatient and selfish that he ruins the first job a sphinx has gotten in over four hundred years?"

"Er, is it me?"

She growled.

Percy took a step back.

"Yes," she said with gritted teeth. "It is you. You may pass, you cruel, awful boy."

With that, she literally melted in the ground and the way was clear. Nico turned and gave him an incredulous look. Percy just shrugged.

"Annabeth told me the story," he said. "That was the same riddle a sphinx asked Oedipus. Annabeth once said how she'd like to meet one so she could solve a new riddle, and I told her she was crazy."

"That does sound like her," said Nico.

They walked the rest of the way and they reached the cave exit. Percy turned to face Nico, and his form flickered. For a fraction of a second, he looked like a faceless mannequin. Nico gave him a sideways, guilty smile.

Percy cursed himself. He'd known he wasn't real. He knew there was no way that this was the real Nico. Why had he subconsciously allowed himself to hope that that wasn't the case? A large part of him wanted it to be him, but a tiny part had actually believed it might be a possibility. For the third time he felt like he'd lost him.

Percy turned his back on him and the maze and tried to bury those thoughts. This wasn't the time for this. There'd be plenty of time to let his grief resurface later. Right now, he needed to find Reyna and Jason.

He hadn't even finished that thought before the two demigods in question literally walked out of thin air. All three of them looked at each other, startled. Once the surprise factor wore off, it became clear that everyone had seen something equally distressing.

"So you both went through a maze too?" Percy said.

Jason gave a short nod. Percy couldn't read his expression.

Reyna also nodded, but looked crestfallen. Percy supposed if neither of them were ready to share just yet, then he'd hold off for now too. It was probably better that they just press on, anyway.

Percy did a full look around the cave and realized it really was a different one than the previous. It was a lot smaller and differently shaped, but didn't let in any sunlight. Instead, lanterns hung from the ceiling on chains which gloomily lit the entire area. Behind them was the exit from the maze. Ahead was a new tunnel, taller than the other, that also simply faded into darkness.

"Ever forward," said Jason. He took the lead.

They entered the new tunnel and after a bit of walking were transported back to the cave they'd just left. Surrounding them were seven grey ghosts. They looked like people, but had no defining characteristics other than the weapons they used and having the shape of either a man or a woman. The second the three demigods appeared, all of the apparitions attacked at once.

This was the toughest challenge yet. As Percy had suspected, the ghosts weren't intangible and were fully capable of making physical contact with them. They had them outnumbered seven to three and seemed to be perfectly designed to exploit their weaknesses. The demigods each took two at once while the extra prowled around near Jason, not yet attacking. That one worried Percy, but there was nothing he could do to get at him with two more ghosts relentlessly attempting to murder him.

It took some time and a bit of luck, but Percy managed to slice through one of his foes' heads. The apparition vanished instantly, which left him in a one-on-one. At that point, it became easier for his skill to take him to victory, but he still had a tough time of it. Soon enough, though, he took that one down too. He turned toward his friends and only needed a second to decide which one needed his help. Reyna was down to one while Jason was still fighting two, plus the third that was just watching him.

He made his decision and stepped in to help Jason, but was a second too late. The son of Jupiter did a rather impressive trick with his sword where he parried two simultaneous attacks and pushed one back, but in that instant, the spare apparition surprised him and cut into his left arm. He instantly cried out in pain and stumbled back a few steps, blood quickly beginning to leak from the wound.

Percy stepped in and got the three ghosts' attention. He fought with a renewed vigor and sense of anger, but even with his injured friend's help, he had to go on the back foot. For over a minute, it was all they could do to avoid either of them getting hit again, but then Reyna finished off her last enemy and jumped in to help. She managed to surprise the ghosts and immediately take one out, and then it was three to two in their favor. Even then it still took longer than you'd expect for them to finish off the last two.

As soon as the final one had dissipated into nothingness, Percy pulled out his dagger and cut away a long strip of fabric from his tunic, which left his midriff bare. Reyna had already forced Jason to sit down by the time he finished. He knelt beside him and wrapped up the wound as tightly as he could.

"Thanks," Jason said, clearly in pain; the cut had been pretty deep.

He started to try and get up, but Reyna held him down.

"We're taking a couple of minutes to rest," she said sternly.

Jason sighed and reluctantly laid back. He used his healthy arm as a pillow and looked over at Percy.

"You see why we Romans like to wear bulky armor?" he said lightheartedly.

Percy chuckled and rolled his eyes. "Yeah, yeah. I still prefer to fight without it."

After a few minutes, Reyna allowed Jason to stand up. Percy had told them about seeing Nico, and then Reyna defeatedly said that her guide had been Hylla. She seemed to think that all but confirmed her death, but then Jason told them that Piper had guided him through his maze. He wouldn't tell them why, but he was so sure she was still alive that Reyna's spirits lifted. Percy could tell she still didn't like the implications of seeing her sister in here, though, and in all honesty, neither did he — he wasn't about to say that out loud, though.

They continued onward and through the tunnel again. This time, when they reappeared in the cave, they were surrounded by a couple dozen walking corpses. They were people but with rotting flesh, exposed bones, and comically slow movement. They weren't even a challenge. They were so slow and useless that a single slice of celestial bronze was enough to put them down for good. Of course, when Reyna hurt them with her regular, mortal-forged sword, they seemed unbothered by the damage inflicted upon them. Even with only Jason and Percy able to damage the undead, it took less than two minutes to finish them all off. Afterward, they hastily went for the tunnel again as the stench was quite atrocious.

As they proceeded onward, the Hollow still made zero sense and had a complete lack of obvious rhyme or reason. The next two times they went through the tunnel, the cave had been completely empty and they were able to just go right on through unhindered. After that, they fought more undead and then found the cave empty again. This time, though, Reyna noticed something.

They were making their way to the tunnel again when she suddenly stopped and pointed at the wall. "Hey. Do you see this?"

Percy followed her finger and saw something carved into the stone. The three of them walked up to it to examine it more closely. A line of characters about the length of his arm was etched there. Percy recognized a handful of Greek letters like theta, sigma, omega, etc. as well as some Latin letters. There were more symbols he thought might be Egyptian and then the rest he didn't recognize at all. Needless to say, he couldn't make sense of it. Judging by his friends' confused expressions, neither could they.

Percy took a step back and saw another disparate line of letters from various alphabets nearby. He pointed it out, and then they all looked around for a minute and found several more scattered across the cavern. Percy was positive they hadn't been there when they first left the maze. His guess was that more and more kept appearing the further they progressed.

After some fruitless thinking about what any of it could mean, they gave up and pressed forward. Next, they fought some more miniature versions of the automaton from the entrance. After that, they faced another batch of ghosts. No one got hurt this time as there were only four of the apparitions, so they were able to swiftly claim victory and continue on their way.

Three more trips through the tunnel and they finally reached what looked to be the end. They faced more challenges each time. The first two involved combat and the last one had a singular, unarmed ghost. Instead of fighting him, one of them had to sit down and play him in a game of Petteia — a popular board game around Greece that only Reyna knew the rules to. It took a bit of time, but her knack for strategy netted her a singular victory, after which the ghost vanished and they moved on.

Percy couldn't help but notice how sullen Jason had been acting since the maze. Even when they took a moment to comment on the obstacle they'd just overcome, he'd been unusually quiet. Reyna seemed to notice too and when she asked if something was off, he just set his jaw and faked a more cheery expression before telling her he couldn't be better.

Going through the tunnel the final time brought them back to the cave once more. The walls were now covered with indecipherable writings. Standing opposite them, instead of the tunnel entrance, was a strange altar. It looked kind of like a wall fountain in its design but didn't have any water, and it was sculpted directly into the stone. A small bowl was held up by three intricately carved hands that stuck out from the base of the wall.

Above it was a sculpted mural depicting three old ladies working a thread. One spun fibers to form the thread, the other measured it, and the third was in the process of snipping it with a pair of shears.

"It's us," said Reyna.

Percy looked at her strangely.

"Our parents, I mean," she tried to clarify.

"I don't remember having the Fates as my parents," said Jason.

She furrowed her brow. "What? No, there."

She pointed inside the bowl. Percy hadn't noticed it before, but there were three symbols etched into it: an eagle, a trident, and a crossed sword and torch.

"Oh," said Percy.

"Jupiter, Poseidon, and Bellona," Jason murmured.

One thing was made clear — they definitely were meant to have come here. One thing was still very uncertain, however — what were they supposed to do now? Clearly, something was meant to go in the bowl, but they had no way of knowing what.

It took some thorough examination, but Percy finally noticed that the text directly above the altar wasn't complete gibberish. Amongst the random assortment of letters from diverse languages was a single word written entirely in Greek.

"Blood," Percy read out. He pointed so the others could see it.

"It wants blood?" said Jason.

"Looks like it."

Jason stared at the word for a second longer before beginning to unwrap his wounded arm.

"What are you doing?" Reyna said, alarmed.

"Giving it blood," he replied. "I'm already bleeding, so may as well try it. I'll wrap it back up after."

He successfully freed his arm from Percy's makeshift bandages and touched his fingers to the bloody skin beneath the wound. He then rubbed his fingers inside the bowl while Reyna instantly rewrapped the injury.

After several seconds, Jason said, "It probably needs more."

"Or maybe it needs some from each of us," Percy suggested.

Neither of them got the chance to test their theories, as just then the eagle suddenly began to glow. A few seconds later, the ground rumbled and the entire wall started sliding downward with the altar. The three of them instinctively retreated several steps back and watched in awe as the cave wall slowly disappeared into the ground.

Soon enough the wall was completely gone, revealing a much, much larger cavern behind it. It stretched out far into darkness, but the floor only proceeded a little farther before stopping at a massive chasm. The edge jutted out in the shape of a triangle with a rounded tip. At its point were two marble plates inlaid into the ground. Across from them in the distance, they could see a cliff at the other side of the seemingly bottomless pit. Percy didn't even get a chance to contemplate how they were supposed to get across before a horrible chill swept over him, raising the hairs on the back of his neck.

The three of them turned around in unison. More ghosts than before had appeared. The first time, they struggled just to take out seven, but now there were twelve. Percy started counting their odds, but then more appeared. There were fifteen, eighteen, twenty — rapidly it became too many to count.

"This is it," Jason muttered.

"This is what?" Percy asked, unable to keep panic out of his voice.

A massive noise echoed across the room that made Percy grip his sword tighter. It had been caused by the apparitions all drawing their ghostly swords in unison. The first few began taking leisurely steps forward and soon the rest were advancing as well.

"What do we do?" Percy said while taking a stance. "We can't beat that many."

"Back up," Jason said.

"Are you crazy?" Reyna asked.

Jason stepped in front of her and began walking backward, forcing her to do the same. He also extended his injured arm in front of Percy as he did this, so he had to follow his lead. Percy glanced behind him and the ledge was getting too close for comfort.

"Jason, stop," Percy said.

He did. The ghosts were getting closer now. He turned away from them to face his two friends, and his face shattered Percy. The son of Jupiter wiped a single tear from his cheek, and his eyes were filled with a fearful determination. He took a step back toward the ghosts and raised the tip of his sword at the two of them.

"What are you doing?" Percy asked. His voice cracked.

Reyna retreated one more step, and then chains shot up from the ground and surrounded her. Percy looked at her and saw the back of her foot had just barely touched one of the plates. The chains pulled her so she was standing completely on it and cocooned her all the way up to beneath her nose. Percy had no chance to react as the section of the ground she stood on broke off and shot across the chasm at lightning speed.

"Reyna!" Percy shouted.

"Percy," said Jason. "Find Piper for me. Tell her I never meant to leave her again."

Percy's eyes widened as realization set in. There was one plate left, and two of them.

"No," he said sternly. "Jason, no. You can't —"

Jason swung his sword and Percy instinctively raised his to block. The son of Jupiter pushed forward and Percy couldn't stop himself from stumbling back. His foot touched the marble and chains wrapped around him and covered his mouth. Time seemed to slow down as the ground he stood on broke away. The ghosts reached Jason, whose back was turned to them.

Percy began to fly across the chasm as the blade of a ghostly sword erupted from his friend's chest, sending a stream of blood through the air. Jason got smaller and smaller until the chains suddenly dropped and Percy fell backward. His back connected with the ground on the opposite side of the pit.

"No!" Percy screamed.

Reyna shakily pulled him to his feet, and they both watched in horror as more of the ghosts plunged their weapons into Jason. The son of Jupiter collapsed to his knees, and then fell forward over the edge. He plummeted off the cliff and disappeared into the darkness.

"Jason!" Reyna shouted.

Percy dropped to his hands and knees and slammed his fist into the ground. Tears began to pour from his eyes and he sobbed. A sound echoed from down below — a single loud thud as Jason's body reached the bottom.

A/N: . . .

There's a bonus mini-chapter going up on Saturday. A full-sized chapter will still be coming as scheduled next Sunday.