This will be an AU and Time Travel fic. The Doors of Death were closed but Percy and Annabeth are forever lost to Tartarus and the remaining Heroes plus Nico defeated Gaea, sealed and banished her. But because the gods were preoccupied by Gaea, they didn't notice the other primordial gods rising until it was too late. Ouranos decided to avenge his wife among other things and declared war against the gods and demigods.

I do not have a beta and my last English mark wasn't all that good, so forgive me if I make any typos. And as for anything that differentiates from canon, well, I did say that it was AU.

I accept criticism, but please, no flames.

Disclaimer: I do not own any of Rick Riordan's work. (Why would I write here if I was? And Nico would totally be the main character.)

Impossibility 1, The Son of Death and the Abyss

Sometimes, Nico wonder if there was anything he could have done to make better, if he could have somehow stopped Percy and Annabeth from falling to Tartarus and maybe find a better way to close the Doors of Death, a way that didn't leave anyone trapped in the deep abyss or potentially dead. Every night, the possibilities would haunt his nightmares and make him unable to sleep peacefully, but when the first ray of light appeared over the horizon, he'll ruthlessly push it to the deepest part of his mind, secure it with so many layer of securities that even the gods would not have been able to drag it out to the forefront of his consciousness, and lamented the loss of another sleepless night.

After all, with the states things are, even being distracted for one second can be fatal and the son of Hades had no urge to become a permanent inhabitant of his father's realm anytime soon, not that he feared death. As a son of Hades, Nico knows better than almost everyone (the exceptions being of course his father, and other gods somewhat related to death) that death was just a part of life and everyone died, even gods can fade away. No, he wasn't afraid of death, but he would like to help prevent the apocalypse before he died, or at least make his death have some sort of meaning.

But it seems as if what he want doesn't really matter in the grand scheme of things, because he was staring at death in the face, or more precisely, he was staring at Tartarus. Now, people might wonder Hades Nico di Angelo was thinking, coming to Tartarus, the most horrifying, darkest, and deepest area of his father's realm, when he narrowly escaped death on his previous visit. The now 16-year-old himself agreed that he would have to be insane to even consider revisiting the abyss. Which is why Nico wonders why the Hades he hadn't yet ran away screaming and sounded the alarm when he entered the Hades' cabin only to find Tartarus sitting calmly on his bed. Though, he mused, does it really counts when it wasn't actually the deep, dark, terrifying abyss he was face to face to, but instead the primordial god of the Abyss.

Nico took a step back and summoned his sword, Kokumu from the shadows. He might have also summoned two dozens skeletons from the underworld, and a couple hellhounds, and hellfire, but who can blame him, even then he stood no chance against a god, not to mention a primordial god. In addition, he just came back from the battlefield and his bones ached from the strain of fighting hours non stop. The conclusion? His odds aren't looking very good. As if to mock him, the god in front of him appeared unaffected by all of Nico's precautions and instead looked amused. Nico took a few seconds to scrutinize the being in front of him.

He didn't know how he immediately recognized the tall, pale-skinned, dark-haired man as Tartarus, there was nothing to even indicate that he wasn't even human except his eyes, and even then he had to put some effort in seeing through the Mist. The being's eyes were dark and endless. Occasionally, something could be seen moving in the dept, but the raven-haired boy focused to see it clearer, it would disappear and Nico will catch sight of something else to distract him.

"What was that mortal phrase again? Oh right, 'take a picture, it'll last longer'."

Nico reeled back in shock at the deep, silky voice and resisted the urge to flush bright red. By the amused look the god shot him, he wasn't all that successful. It was at times like these that Nico cursed his pale skin; his previous olive skin tone was much easier to hide any color.

"Who are you?" Nico demanded, despite already knowing, because he wanted to deny that the being in front of him was who he thought it was, because it didn't make any sense that out of so many half-blood, he appeared in front of Nico, who despite all his effort was still seen as the weakest of all his father's children, who despite his contributions and sacrifices was still the least liked of all the Big Three children. Even Jason Grace who was Roman and not Greek was liked better here at Camp Half-Blood, because, the campers whispered when they thought he wasn't looking, Nico di Angelo was the one who let Percy Jackson and Annabeth Chase fall. And somewhere along the line, it became Nico di Angelo pushed Percy and Annabeth down, because he was jealous and wanted to steal Percy's glory, he caused their death, he killed them. Because even if their death weren't confirmed, they were in Tartarus, part of the realm of the dead, and they were as good as dead. Nico heard them through the shadows loud and clear, after all it was his domain, but he made no move to correct them, since in a way he did kill them. If only he had been faster, if only he had been stronger, if only he hadn't been captured in Tartarus. And no one defended him, because Percy had been his only true friend at CampHalf-Blood and now he was gone gone gone and never to come back.

Tartarus raised an eyebrow and quirked his lips into a half smile, as if aware that Nico knew perfectly who he was, but even if he thought so, he made no move to point it out and instead indulged him with a response.

"So you don't know who I am? I'm hurt," the god placed a hand over his heart and gasped dramatically, "and after we spent so much time together. But," Tartarus straightened and stood up to his full height of 6'2, a full 4 inches taller than Nico's current height of 5'10, "if you want a proper introduction, you just had to say so."

Nico took half a step back when Tartarus made to step forward and then in a surge of anger took a full step forward to stand his ground.

"I'm Tartarus, primordial god of the Abyss, son of Chaos, father of Typhon." He mockingly stretched a half bow. "Pleased to meet you, Nikodemos di Angelo, son of Hades, King of Ghosts, Ambassador of Pluto."

And right there and then, before Nico could react, the summoned creatures were banished, the hellfire was extinguished, the god disappeared, pain exploded in the back of his head, and the last thing he heard before fading into unconsciousness was the voice of Tartarus.

"Nighty night."

Tartarus caught the boy just before he fell to the ground; after all it wouldn't do any of them any good to have damaged goods. They had big plans for the boy and it wouldn't do for him to break too early, besides, he had grown fond of the boy during the time the son of Hades had spent in his domain.

"Finished?" A voice drawled, "You sure took your sweet time."

"Oh stop your whining," Tartarus replied without turning around, "after all, we literally have all the time in the world. Isn't that right, Chronos?"

The distinctively male voice humphed, "That may be so, but we in no way have infinite patience."

"Fine, fine. Go back to base and I'll follow shortly after you. Then, everything is to be proceeded as planned."

There was a bright flash and Tartarus knew the primordial god of Time had left. He looked back down at the boy in his arms and thought to himself that maybe won't go as planned. He had grown to like the boy and the child could use some extra help. At the end, things might even benefit him greatly.

The primordial god of the Abyss nodded to himself, decisions made, and in another flash, the cabin was once again empty.

Chrono is the primordial god of Time while Kronos is the Lord of Titans and the Titan of time and agriculture. They are often confused but they are two different primordial/titan.

Please review on your way out.

Tsuki Hikaru