Tartarus was guiding her.

The path persisted, perfectly clear. She glided over shadows, preventing the jagged rocks from slicing open her soles. The fog flanked each side, the winding route sloping more and more as it approached the edge of a cliff.

The closer she got, the faster her heart beat, a strange warmth flowing through her as her body recalled what her mind couldn't. She knew Akhlys had not deceived her by offering this path— she knew she was going home.

Once she reached the edge, she looked down into the chasm, finding a darkness so deep that for the first time, the unknown unsettled her. Floating three hundred feet below where she stood, was a doorway of black marble, leading into some sort of large room. It was the mansion's entrance, but she couldn't even see the mansion.

Further down, between the cliff and the doorway, was an abyss she recognized even without having been there. Or, at least, not having been there when she was conscious enough to remember it. Nothingness– Chaos.

It was marvelous even if she knew what falling in would have in store for her. Chaos, her great-grandparent, the one all stemmed from. She'd be lost in there forever.

(Hadn't she always felt lost in life? Out of place in the mortal world?)

Emilia willed the shadows to form a bridge, carrying her down to the doorway and avoiding the fall into Chaos. The shadows seemed to curl on their own, ghostly limbs pointing toward the Mansion and newly formed heads cocking eagerly like puppies guiding their owner to something exciting.

The darkness pushed her ahead, and the shadows flowed at her feet like a red carpet. As the doors loomed over her, there came a flutter in her stomach, a sense of familiarity she hated being unable to place. In there was her legacy, the part of her she had only scratched the surface of.

She wondered if Eris would be waiting, eager to see her. Would it be so? Or would she resent having chosen to return to Tartarus for her? She could be welcomed with open arms or a sneer.

She assumed she was safe here but perhaps the opposite was true, and she'd kidded herself into thinking the Mansion of Night would resonate like home.

She reached the doors, placing her palm over the handle, far too big for her to fully grasp On command— or perhaps the shadows had turned it for her; they seemed to have a will of their own here— they opened, clearing a space for her to enter.

Atlas had once told her that what was within the Mansion of Night was not meant for mortal eyes. It could lead to madness that could never be cured, not even by Dionysus. All the horrors of the world were contained in it, a gigantic space filled with suffering that could overwhelm, of darkness that brought so much fright that people could die simply from being scared.

To Emilia, it was just a regular mansion. She entered a foyer made entirely of black marble, a shimmer of purple over each entryway into another room. There was one main hallway ahead, barely visible through the curtains of dark energy. It seemed to go on forever, with massive doors on either side.

The ceiling must have been at least sixty feet over her head, but she wasn't entirely sure it ended. In the center of a glittering dome hung what could have been a chandelier, though it sparkled and changed form so often that she assumed it to be another mass of black energy, dark matter that simply swirled in place to decorate the entrance hall.

She heard whispers all around. Further ahead, screams of agony. Whimpers, scratching, cackles. None of it unsettled her. She remembered watching horror movies with Pollux and wondering why mortals were thrilled by them. These sounds were the same ones she'd thought to hear alone in her room as a little girl, under the impression that no one cared.

Had her family been whispering to her all her life? When, in the dead of night, she found herself feeling alone, had she ever truly been so?

She chose a doorway at random, entering the room to her right. Within, she found a large empty space, like a bare ballroom with half-pillars along the walls and artistic protrusions that made the shapes of demons— limbs, faces, wings— snarling beasts that seemed to move as the energy swirled over them, shadows in constant motion. Whether they were decorations made in their likeness or actual demons trapped there, she didn't know. It reminded her of gargoyles. The demons chittered and she didn't feel anything. Perhaps, at best, it amused her.

She heard a light thud in the corner of the room. When she turned, she saw two small figures curled up together, eyes closed. She rushed to Percy and Annabeth's side, stunned at their new appearance. They seemed to be dead. Their skin was sallow, eye sockets dark and sunken. Annabeth's beautiful hair had dried into a skein of cobwebs and Percy's looked like a genuine rat's nest, a disarray of weeds.

They looked as if they'd been stuck in a cool, dark mausoleum for decades, slowly withering into a desiccated husk. Around them swirled blobs of Akhlys's white mist. Because of it, she could faintly make out their breaths, causing the fog to curl at their nostrils.

"Oh, gods," she whispered, kneeling next to them. She supposed Akhlys had kept her promise. They were alive and sleeping. She realized she said nothing to Akhlys about them ever waking up. "Hey. It's going to be okay. We're going to get out of here soon. We're almost there."

"Your voice changes when you speak to them."

She stood without turning, the voice all-too familiar now. Emilia braced herself, drawing a deep breath before she glanced over her shoulder, her mother almost one with the shadows of the house, so dark that Emilia could only make out her face because the goddess was choosing to appear as human-like as possible, the same way she'd come in her dreams.

"You're here," said Eris, voice catching. "You're home. You have not been here for two decades."

"Mother," said Emilia awkwardly. How should she greet her? With a hug? A wave? They hadn't exactly spoken since the day Eris apparently decided to leave Gaea.

Eris floated over to her, lowered so that she was closer to Emilia's height. She must have shrunk herself down tremendously. The goddess extended her hands, fingers constantly shortening and elongating as the shadows pumped over her body. When Emilia didn't draw away, Eris cupped her face, the shadows caressing Emilia's cheek.

Emilia didn't mean to burst into tears.

"Little one," sighed Eris, smoothing a hand through Emilia's hair. "I can only imagine what you feel. Your body remembers being created here. You've never felt you belonged anywhere because this is your real home."

She felt the shadows extending over her like a blanket, a thousand arms patting her back soothingly as she covered her face, shaking her head and refusing to believe that was the reason.

She missed her aunt, Pollux, Hylla, her siblings, and her friends. Why, then, did she feel like this was a place she wanted more time to explore? Why, then, did she imagine staying here?

(She remembered Eris had once told her that she– though Emilia would never want to acknowledge it– turned to rage when the people she loved were hurt. It made her afraid of what she could do, it made her imagine what she could do to the world if it upset her enough. She had become the hero but at the cost of holding herself back. Here, darkness was free. Here, Emilia had total control. No one would hurt her loved ones if she willed it to be so. Nothing could stand in her way of protecting them.)

She hated imagining that the Pit could offer her something longer, something more secure. A place to draw from constantly. In thinking it, she felt like ailing. As strong as she was here, she'd never felt so conflicted, so powerless.

Eris hummed, the shadows vibrating into Emilia as if three Small Bobs were laying on her and purring. It calmed her slightly. "When you return to the mortal world, you will never again feel this," whispered Eris. "This belonging. My siblings and I were not meant to sire children. Least of all those most like me. I have brought into the world a being that could never be fully accepted by it. I... I caused you harm by creating you. I set the course of your life. I am powerless to fix that for you. To give you everything you want and need at the same time. Over and over, my choice has forced more of them upon you. You cannot have it all. There will always be something you must sacrifice because of what I did. Because of the imbalance I created."

"Do you regret making me?" asked Emilia, squeezing her eyes shut.

"No." Eris shook her head, voice soft as silk. "I should not have succumbed to what Gaea wanted... you were right, my mother was cold and I gave in. In doing so, I put you in a terrible position, I granted you a lifetime of danger. But somehow, despite it all, you came to be as you are now. You are... the only child of darkness to achieve love. You created a family for yourself, a name for yourself. I envied that but I came to admire it. Even here, you are surviving, all to get back to them. I don't regret creating you. I regret... what you suspected I'd come to hate. The fact I wasn't able to raise you. The fact I never did more for you and now, I've caused all this."

Emilia didn't know what she wanted to hear from Eris. She didn't know if she had expected an apology, if she craved praise. She just cried, she mourned the mother she barely knew, she mourned the loss of the normal life she'd fought to have, she sobbed in fearful anticipation of what would come next. She didn't even want to think of it.

"I just want to go home," said Emilia between sobs. "I want to go home but here feels like home. I don't know if I'll ever be the same again. Why..." She wiped her eyes. "Why did you finally choose to come?"

"I followed your example," said Eris. "I trusted you. I imagined having a family and... well, Nemesis came to see me, because of you. She saw Leo Valdez's devotion to you. She spoke to me, she helped me see what you wished to show me. I wanted to be here when you came home. I decided that if there is a chance for us to know one another, a chance for me to be accepted by the gods– accepted by myself, despite all the wrongs I've committed– then I must help you close the Doors. I must see you get back to the mortal world so that you may have everything. I will give you what I never did before."

Eris sighed, glancing sadly over her shoulder as if afraid to meet her daughter's gaze. "You showed me I deserved to feel the things I didn't think were possible, little one. I will not be used. If Gaea wishes the Doors to remain open, I will see them closed. I wish you to be able to return to the world where you have your friends, your family. It will never erase the memory of what I failed in but... I hope it will be a start. For you to perhaps one day care for me as much as you care for the others. For me to know you, truly, and be free of my own judgment and fear."

Emilia sniffled. "Gaea will stop using me as an anchor. She had me anchoring you. When she no longer needs me, I might... I might..."

"Shh." Eris shook her head. "I don't know what comes of that. It was never... never planned out. But I make you this promise, my sweet winter child... my little shadow. When you most need me, I will be there. I swear it to you. This oath, I will hold, to make up for all the times I failed you. On the River Styx, I swear that I will see this through with you until the threat is vanquished."

Emilia couldn't stop herself from leaning into Eris, burying her face in her mother's chest and crying even harder. It didn't feel fair for her mother to be good now. Only now, after everything that'd happened, after all they suffered. But it also wasn't fair that she'd felt so alone, so unappreciated, that like Emilia, she'd been drawn down the wrong path. It wasn't fair any of them were being forced into this.

No, she'd never been afraid of her mother. She'd just wanted her love. She wanted to know who she was and what gifts she had for her. Even if she couldn't have a normal life, Emilia wished that Eris had been present earlier. She supposed it was never too late.

But what if she didn't live very long after this?

"I can't stay," said Emilia, drawing away. It was almost done by force. She hated to think that she wanted to stay here, that she wished to explore the house, meet her mother's other siblings, maybe even her grandmother. But she had a quest to complete. She had to get out now. "We have to go, we can't be here. Percy, Annabeth, this realm hurts them. I need to get them back. I need to get back to... to Hylla. My girlfriend, who I love. I need her."

She watched Eris's gaze soften, perhaps mournfully. Had her mother had the chance to love anyone like that? Could she ever? "I want you to be happy. As much as it pains me to let you go, I hope... we will see each other again, very soon. And when this is over, perhaps, we could have our little chats whenever you'd like. You are my only child. You will always be my only child. I will not forsake that. But please, before you go, indulge me for just a moment. I have gifts I still need to share with you, things you can still learn before you return to the mortal world.

Emilia dried her eyes as Eris stepped away. "Here." The goddess held out her arm, the other gliding over it. With one swift movement, she opened a cut on her arm. From it flowed a thick liquid, like gasoline, with flicks of golden ichor. "I heard you wonder in the night if you could heal. You can, my dear, if you try."

She flicked her fingers over the cut, the shadows coiling and creating a layer over the injury, like a bandaid. "You brought the arai back here by sealing them away in darkness. So in darkness, can you seal a wound. Only a minor injury, of course... even some abilities I do not have. Cuts, bruises, scrapes, the sort of things that slow a person down even just... you can use darkness to mend them." When she stopped moving her fingers, the cut was healed.

Eris rippled further away, the shadows extending outward in a pulse before they curved back like ocean waves, crashing into Eris and making her disappear. Her voice radiated from where she stood, "So, too, can you be present without seeming so. You've learned to shadow travel continuously, swiftly enough you seem to leap through time and space. But shadows persist even in the daylight. In darkness we find it easiest to linger, but even with a beating sun, you can hide within shadows. You can call them to conceal you, draped over you like a blanket. You can become invisible, perfectly still and held within the nearest shadow, able to exist without another knowing."

The goddess came closer once more. "And last, you've already seen how you can manipulate creatures of darkness. Nocturnal animals are easy... owls and bats, mostly. It's what my mother does at night. Never forget what your mother's side offers you, little one. Even when you leave this realm, you will never be weak. You will only ever lack power if you hold yourself back. When you focus on love for your friends, focus on strength for yourself. Grant it. You chose to learn to un-sow discord. In the same manner, you can use darkness for good. You'll be the only one of our family who attempts such things, but... then again, a different path was chosen for you."

"Thank you," said Emilia. For a moment, she imagined being a little girl, having her mother teaching her how to control her powers each day when she returned from school. If she had a daughter, she'd make sure that was the case.

She was stunned to find herself thinking of that, in a moment like this. Did she want a daughter? Could she have one? Would that child even have powers of any sort?

It made her remember Hylla, it made her remember she had to get back to her. "Mother," said Emilia softly. "I think I have to go now. I can't say. I wish... I would like to... but I can't."

Before Eris could respond, there came a rumble from the foyer. Eris pursed her lips. "She's returned. Are you ready to meet your grandmother?"

Emilia wasn't sure how to answer that. "Will she let us out of here alive?"

"She will. She once watched over you, in those moments where the dark was your only solace. She is unkind to those who come near her... few here would dare anger her. But you are family. This, she will not forget. She will not stop your journey... because even in Tartarus, we believe in balance."

A presence entered, a form so vast and shadowy that Emilia would've known who she was even if Eris hadn't introduced her. She was forty feet tall, a churning figure of ash and smoke. Her dress was void black, mixed with the colors of a space nebula, as if galaxies were being born in her bodice. Her face was hard to see except for the pinpoints of her eyes, which shone like quasars. When her monstrous black wings beat, waves of darkness rolled around them, a sensation that made Emilia's eyelids feel heavy.

She spoke with a voice as soft as coffin lining, "At last, the whole of our family is contained within my realm."

"Mother," said Eris, growing in size until she was almost thirty feet tall. "You remember my child. Emilia."

"Emilia," repeated Nyx, her gigantic form slithering down until her face was right in front of her granddaughter, her head almost as tall as Emilia. "A demigod child to rival all others. A darkness to enter the mortal world. I recall. My sister has used you for much. We all heard of your time serving the Titan Lord."

She hated how Nyx said it with pride. "Mother Night," she said awkwardly, not sure what to call her.

Nyx regarded her with intrigue and drew back to full height. "A shame, the way you came to life." She glared at Eris as if to blame her for it. "You should not be here. You should not exist at all. Alas, you do." She hummed, the air seeming to vibrate, darkness bending around her. "My first grandchild in many centuries. My first demigod grandchild... the one to set the tone for the rest. Oh, it was only after you were born that Nemesis and Hypnos left our realm to create demigod children of their own... it is because of you that your cousins exist. You could choose to remain here, child. This is your home."

Emilia stared up at her, annoyed with how much she had to crane her neck. "I have to return to the mortal world. I have to defeat Gaea. I have to go now."

Nyx's lips curled. "The promises that one makes. It's often too much for some to resist." Again, she side-eyed her daughter. "Gaea understands little about the place of darkness. My reach can only go so far, while she hungers for more."

She spoke bitterly. Emilia almost fell bad for her. What if that's all this was? Nyx suffered in her own way, she passed the suffering to Eris, and so Eris suffered, too, everyone wishing to be free while able to attain nothing. Emilia was not meant to be free, either. Every bit of choice she'd had so far came with a fight, came with a cost.

It had to end.

"You have an option," offered Nyx. "I can make you a goddess and you can reside where you will never hunger for more. You will be with your brethren, one with Night. Demigods are often such puny creatures, so afraid they cannot behold me... you are different. You are deserving."

"I can't stay," insisted Emilia. "It's time for me and my friends to go. It's time for us to close the Doors of Death."

"Mother." Eris glared at Nyx. "Let her be. I ask for her safe passage, that of her and her friends."

Nyx considered it. They seemed to have a sort of silent conversation, and Eris clearly won. "Let them pass. The Doors lie in the heart of Tartarus– only my brethren are sure to survive there. Your friends... their lives are not promised. Go forth, child, spread darkness back into the mortal world. Do not forget where you hail from. Do not forget the offer I've extended."

"I'm fine as a mortal," said Emilia. She thought of Hylla again, of growing old with her, of having children with her. "Thank you, Mother Night." She bowed her head respectfully, and turned to scoop Percy and Annabeth up with her shadows.

Nyx stepped aside as Eris shrank back down, guiding Emilia back into the foyer, then through the long hallway lined with doors. "Here lies the path to the Doors of Death," said Eris, guiding her down. "Each room is a domain for one of my siblings. A few here... Thanatos, his door is closed because he no longer resides in the mansion. Within are memories of every single death. A mortal could not gaze into it without going mad. If they tried to understand all the deaths, they would feel all the pain in the world at once and succumb to it."

She gestured to the door across from it. "Hypnos, since left vacant. It is a domain of deep sleep, and it forces the mind open to all sorts of horrors. If a mortal were to enter there, they would never wake up, they'd remain comatose and relive every nightmare they have ever had, over and over until sleep itself drives them mad."

Eris brushed her hand against one door. "Nemesis. Retribution, vengeance, all the problems she's ever caused are contained there. It would curse a mortal forever to enter there; she would become personally involved in their lives– if they survived– and ensure their life is balance... even if it means adding more suffering. There is my room, where memories of all wars and strife are carried. Next, Keres, my sisters, the battlefield spirits of famine and disease. Every plague is contained there, all sorts of diseases and poisons. They can grant the power to spread that into the world... but at a cost. The arai..." She smirked when there came a rattle behind the door, "I believe they're trapped in there until you leave. Well done."

Emilia blushed. Eris went on, pointing out where Charon used to linger, where Geras holed up as a withered man who could addle the brain without much effort. Demon after demon followed through the hall, each growing worse and worse, containing every member of Night's family. She explained that Emilia saw the house in its true state– a singular long hallway. To mortals, it could appear all sorts of ways with the intention of running them up the wrong door or simply trapping them in madness.

"Seeing in the dark means you detect what is truly there, even if others are unaware," said Eris as they moved along. "Mortals could perceive this as a maze or find dead ends where they don't exist. You, however, see past these magical defenses. Just as you can hide in the dark, you can also find what it obscures. It's enough for you to conceal yourself without needing the Death Mist. Night itself will protect you."

Eris swept her hand over the apparent door at the very end of the hall, darkness making way to reveal it wasn't a door at all– it was an opening into the outside of the mansion, a rocky path that dropped off into a raging body of water.

"This is where our border ends," said Eris. "The Acheron... the River of Pain. We are not easily able to cross it because all we bring is pain. It overwhelms us. You, my dear, should be able to form a bridge of darkness over it. Once across, you will be at the heart of Tartarus."

"Thank you, Mother," said Emilia gently, checking that Percy and Annabeth remained asleep. "Will they wake when we cross?"

She nodded. "The spell on them will break. You must be ready to fight." Eris cupped Emilia's face, a solemn look on her face as she examined her daughter, perhaps wishing to remember what she felt like. "As my mother told you, your birth allowed for my siblings to have their own demigod children... you weren't just an anchor to the monsters, you were an anchor for all beings that resided in Tartarus. So long as they crossed the River Acheron, they could follow a path of darkness out into the world. They followed you. I... I could not bring myself to do it, no matter how hard I tried. Gaea had to bring me over when she wished for me to turn you. I hope that... soon, of my own accord, I can come and go as I please."

Emilia examined the river, listening to the roaring current, thousands of voices crying out– shrieking in agony, pleading for mercy. Murderers trying to explain themselves, others telling Emilia that she was a devil, a killer, a monster. They spit at her the names of those who had died in service of Kronos, the same demigods she brought to him.

"I hope so, too," she said at last to her mother. "I... I still remember the things this river tells me about. The feeling I had in the hall, the suffering your siblings inflict on the world... I recall when I would radiate misery to those around me without understanding it. Even now I consider it and I find something beautiful in darkness, in the abilities we have. The world is balanced between good and bad– suffering can change people. It is... awful, I think. But I am proud of the person I am now. I no longer resent what I had to go through in order to get to that point. I am not afraid. Whatever comes, I will face it."

Eris's eyes seemed to darken, and at first Emilia worried this was a bad sign, until she saw a faint purple glow and realized she was tearing up. "You did things I could never manage to do. I am proud of you."

"We will meet again," said Emilia, offering a small smile. "It's time. I should cross now."

"I wish you the utmost luck, little one." Eris drew away, watching silently as Emilia coaxed the shadows into forming a bridge over the twenty-foot stretch of water. She looked back after the first step, her mother nodding in encouragement. By the time she reached halfway, Nyx's domain was no longer visible. Eris was gone.

Percy and Annabeth awoke with sharp gasps as they reached solid ground on the other side. Emilia was quiet for a moment, letting them gather their bearings before she told them as briefly as possible what'd happened. There were more important things to word about.

Ahead of them came a dim red glow from a valley big enough to fit the San Francisco Bay. A booming noise came from the entire landscape, as if thunder were echoing from beneath the ground. Under poisonous clouds, the rolling terrain glistened purple with dark red and blue scar lines.

The center of the valley was covered with a fine black fuzz of peppery dots. It was far away, but Emilia had a bad feeling it was an army– thousands, maybe tens of thousands of monsters, gathered around a central pinpoint of darkness. The Doors of Death.

There came a skittering of a rockslide in the hills to their left. A patch of glowing white hair appeared over the ridge, then a familiar grinning face with pure silver eyes.

"Bob?" Annabeth looked relieved. "Oh my gods!"

"Friends!" The Titan lumbered toward them. The bristles of his broom had been burned off. His janitor's uniform was slashed with new claw marks, but he looked delighted. On his shoulder, Small Bob the kitten purred almost as loudly as the pulsing heart of Tartarus. "I found you!" He gathered them in a rib-crushing hug.

"How did you get here?" asked Percy, wiggling his way out of his arms. "Through the Mansion of Night?"

"No, no." Bob shook his head adamantly. "That place is too scary. Another way– only good for Titans and such." He looked at Emilia. "You do not look like a smoking dead person."

"I have my own way to hide," said Emilia. "It's the final stretch now... let's see if the Death Mist works. We'll move quickly and quietly and hope that... nevermind."

There was no need to elaborate. In silence, they continued onward. Emilia turned back to look at the darkness one last time, wishing that she didn't feel so empty.