I always felt like nico and Percy shared a brother dynamic that really is never portrayed so this is my take on it probably a one shot.

Disclaimer. I do not own Percy Jackson. The person who dose is a complete genius

Nico sighed and buried his head in his hands. Percy was missing. Percy. Was. Missing. How was he supposed to deal with this. Percy was his brother in all but blood. He called Percy's mom 'mom' and Percy had given him half of his closet. He had a small pullout bed in his room for when he would randomly sleep over and a secret stash of gummi bears hidden under his bed just for nico. What he wasn't allowed to have a secret obsession with the most fantastic chewy object ever invented.

And he wasn't going to lie he had lost sleep over Percy before. I mean the idiot took practically every risk in the book with only Annabeth to stop him. That boy got in so many near-death situations that he couldn't help losing sleep anymore. He knew of course that Kelp Head could take care of himself. I mean he had the curse of Achilles and all.

That was another thing. When he had persuaded Percy into taking it he had been relieved. Not just because now they had a chance but because now he wouldn't have to worry so much. Every time he went into battle he didn't have to think .' what if he doesn't come out' not that he wasn't confident in Percy's abilities but, Come on no one is perfect and anybody could get hurt. Just maybe the hurting could turn out to be fatal.

He knew he was luckier than most. Able to see the dead after their passing. But what people didn't understand was the difference in the person. They are a shade of what they used to be. He had seen it with Bianca, quieter, more introspective. Also they couldn't touch each other. No matter what they were always dead.

So Nico knew that he had to search everywhere for Percy. No matter what, no matter the risk. Percy could not be allowed to die and leave him with a devil( literally) for a father and a immortal man-hating cousin for family. No he couldn't lose his big brother not after losing his big sister. And Percy was the only real 'family' he had left. He wasn't allowed to die. Ever.