Nico couldn't remember falling asleep, probably because it happened so fast. All he knew when he woke up was that he was there, he was watching Percy and Annabeth, falling down into that (literal) hell hole of a place. All he could think was that it was his fault, that he could've, should've, yet didn't do something.

Second time Percy's landed himself in the Underworld, thanks to him. Except this time, things were much, much worse.

He screamed, clutching the blankets to his chest with his eyes shut tight, because he was scared. Too scared to realize that he wasn't in Percy's room, and that he'd woken up the mechanic, who had been dozing lightly in a chair across the room, drooling on Archimedes' notes that littered his desk.

"Nico?" Leo murmured, still a bit dazed. 'Gross,' he thought, wiping his mouth on his sleeve, 'Archimedes probably wouldn't be too happy about that.'

Nico shuddered with fear, tears threatening to pour from his eyes. He was breathing heavily, which was hard on his lungs, and he coughed into the blankets. "My fault," he choked out, "It was all my fault." Still struggling to breathe, he pulled the sheets over his face and cried for all it was worth.

"Hey there, buddy," Leo said gently, but he winced as he heard Nico coughing. "Ah..." He awkwardly tried to pull the blankets away, afraid that the kid would end up suffocating in the mess of sheets. "C'mon, Nico," he pleaded, tugging at the blanket harder.

After a few more seconds, Nico gave up and loosened his grip on the blanket, allowing it to be taken away. "Leo," he said in a weak voice, "Leo, please. Just leave me alone." His voice was quavering so much that it was a marvel that Leo even understood him, but it wasn't just his words that shook—his entire frame trembled.

Leo just frowned, because just that morning in the dining hall, Nico seemed so much stronger. Older. More confident. But now? He shivered, despite the fact that it was warm in the room, and suddenly he looked much too young and much too vulnerable to be the powerful Ambassador of Pluto. "No can do, sorry," he answered nonchalantly, laying down next to him.

"I said go," Nico ordered, though his voice didn't hold much authority. "Leo, I—I don't want..." he trailed off, swallowing down more tears.

"It's my room, first of all. And second of all, everyone else on board is still awake out there. There's nowhere I can go, even if I wanted to. And you know me—you really think I'd pass up this opportunity to annoy you?" He smiled for a moment, before letting it fade. "Kidding."

For a moment, no one said anything. Nico was debating whether or not it would be worth it to continue protesting, when he decided that Leo, for once, was right. It was already kind enough of him to let him stay in his bed—he couldn't kick the guy out. All he could think to say was, "It's a long fall."

Leo's heart just about stopped. Of course Nico had been dreaming of Tartarus; what else would make someone scream in such agony? He couldn't answer. No matter what he said, it would be pointless. No string of words would undo what he had seen.

"It's a long fall," he repeated, "and I let them go."

If it was possible for Leo to be any more speechless, he was. He'd forgotten that Nico was there at the edge, watching those two hang on for dear life, watching them let go. Suddenly, the words he'd said when he woke up—my fault!—made sense. "No."

"No?" Nico asked, not sure what Leo meant.

"It... It's not your fault, Nico." He flashed back to when he'd fired on the Romans. He swore to himself that he wouldn't let Nico feel that type of guilt—nobody deserved that. "Please believe me," he pleaded, "None of it was your fault."

"But the way he looked at me, Leo," Nico muttered miserably. "Percy was... He was so scared."

Everything about that was wrong. For months at Camp Half-Blood, Leo had heard everyone babble on and on about the missing Percy Jackson—Percy this, Percy that, battled this person, completed this quest, blah, blah, blah—and Leo was overjoyed that he was chosen to build the ship to retrieve him.

Sure, when they'd got there, Percy was wearing a huge purple bedsheet and he looked like an ordinary guy with his arms around Hazel and Frank, but one look at him and Leo knew. This guy was powerful, and any amount of rumors and storytelling at camp would never live up to the real thing.

Even if it kind of sucked that their first real conversation was Percy yelling at him for firing on the Romans, the guy was a hero and nothing less.

Percy Jackson was scared, and it was so, so wrong.

Unable to really respond to that, Leo just frowned, looking just as miserable as Nico did. And he knew something—something he hadn't talked to Nico about. He knew that it was all his fault, not Nico's, all his fault because of that damn stupid fortune cookie. But he didn't say anything, because what could words do now? It was done.

He stared up at his ceiling, and then he glanced at Nico. Very, very slowly, he put an arm around him, then another. Because when words failed, what else was there? Unlike the last time Leo tried to hug him, Nico didn't protest at all, he just let himself stay there, totally still in the mechanic's arms.

Though he had been trembling before, he felt it kind of melt away with Leo there, because Leo was just so warm. Nico couldn't even remember the last time he'd truly felt warm before talking to Leo, just because... well, Tartarus was a very, very cold place. He shifted a bit, before letting out a sigh. He was in a bed that wasn't his, being held in arms that belonged to a person he once hated.

In Leo's embrace, he let himself cry. But he counted—one, two, three... all the way to ten—and then he swallowed down his sobs, refusing to let himself go on after that. Enough was enough.

Leo said nothing, even when he felt tears soaking his t-shirt. After a while, he wasn't even sure if he was comforting Nico, or if he was doing this for himself. Because of course, he blamed himself for what had happened, but Nico blamed himself, too. Somehow, knowing that they shared that painful guilt was enough to lessen it, even a little.

Minutes passed. Fifteen, twenty—the two had kind of lost track of time. Eventually, though, Leo listened and heard that Nico's breathing had steadied, and his figure went limp. The boy had fallen asleep in his arms.

It was calming to hold a sleeping person like that, for some reason. Leo pulled him closer for a moment, holding him securely, yet gently, and he was almost ready to fall asleep himself, but he heard something.

Footsteps, a door opening.

With extreme care, like he was working with a fragile machine, he slipped Nico out of his hold and laid the boy's head on the pillow, pulling the blanket up to his chin. "Sleep well, buddy," he whispered, and he could've sworn that Nico smiled in his sleep.

Then, a brow raised in cautious curiosity, he opened the door a crack. Hazel had just walked out of Percy's room.

'Oh gods,' he thought, 'she's looking for Nico. She must be worried sick.' But the expression on her face wasn't worry or concern, it was actually a pleasant smile, the kind of thing that made Leo want to stare at her for a few seconds longer. 'Snap out of it,' he scolded himself, 'that's Frank's girl.' Even so, he let himself stare at her for a second too long and she noticed him.

"Leo?" Hazel called out in a hushed tone.

Leo blushed, having been caught peeking through the door frame at her. Quietly, he slipped out into the hall and shut the door behind him. "Yup, that's me," he answered sheepishly, letting out a nervous chuckle.

Without warning, she leaned forward and pulled him into a hug, and Leo was almost certain that his heart would burst right there. She held him closely, and it took him a second to return the gesture.

"H-Hazel?" he stammered, not sure of what was going on. "What... uh, what are you doing?"

"I'm thanking you, Leo Valdez." She pulled herself out of the hug. "Nico's in your room, isn't he?"

"What? No, he isn't," he immediately answered, but it was no use hiding it. "Alright, he kind of is. But what're you doing out here?"

"I... I heard him scream. We all figured he was having nightmares, and I didn't want him to be down here all alone... But I should have known." She smiled. "You are just like S—" Her voice faltered, and she just said, "He never broke a promise to me, either."

Leo racked his mind for what she was talking about, when it occurred to him. He'd promised her days beforehand, to watch over Nico while Hazel wasn't there. "Oh."

"Nico... I was worried about him, since he was so different after Tartarus. He was so sure he'd never fit in with us, and I almost believed him, but you didn't let that happen. You really did take care of him, Leo." She put a hand on his shoulder. "Thank you."

"Aw, c'mon, that was nothing," he laughed. Really, compared to what Nico had done for him... it really was nothing, he thought. "He's a good kid. I love angst-y, brooding fourteen year-olds!" he joked, and Hazel just rolled her eyes.

"Okay, I won't tell the others about this, but I have to get back up there." She turned around to leave, but she glanced back. "Tell Nico that I love him when he wakes up, okay?"

"Of course," he answered, and she was on her way. He strolled casually back into the room, and he was relieved to see that Nico was still asleep. He sat down at the desk again, tinkering with a machine for a while, until he let himself doze off in his seat again.

What he didn't know was that Nico was awake, silently listening to his conversation with Hazel. Even if Leo wasn't hugging him anymore, he felt warmed to the bone just listening to his sister speak like that. "Tell Nico that I love him." The words filled him with such emotion that he shed a single tear, quickly wiped away before Leo could return.

Looking at the sleeping son of Hephaestus out of one eye, Nico smiled. Swiftly, he got up and took a spare blanket, draping it over his shoulders, before lying back down in the bed. He fell back into slumber rather quickly, and got the feeling that he wouldn't have anymore nightmares this time.