Perseus Jackson…

Percy startled at the voice hissing through his mind, slipping out of the half-trance that he had lulled himself into by listening to his breaths echoing off the walls of the Poseidon cabin.

It wasn't waking up, because he hadn't been asleep-it had been nine days since he slept, nine days since he laid down his head and he could hear the shadows whispering to him, slipping into his blood and filling him with strength and power that won't let him close his eyes on the night.

It wasn't even close enough to sleep for him to be disoriented as his eyes flickered open, heart hammering. He knew where he was, leaned against the wall next to the door of the Poseidon cabin-he could feel the ridges of the coral digging against his bare back, feel the sweat trickling down his neck and the floorboards pressing against his feet. He could even see-shapes, without their colors, but as clearly as though it were day.

He didn't understand what was going on, and it terrified him. He had been living with that terror for weeks-as he stopped sleeping, as his eyesight grew sharper and sharper in the shadows, and as the ocean started feeling less and less like home.

But the voice-that was even worse. Because he knew that voice…just those two words, his name, threw him hurtling back to memories that he had skirted in his mind for months, memories of staring into a whirling void, of a voice echoing through his mind, mocking him, breaking him down, warning him that his time was up, that he was going to die then and there...

He spoke the name as quietly as he could-and shuddered at how right it felt on his lips. How easy it was to say it, when it had hurt for so long to even think it.

"Tartarus."

Perseus Jackson…You know what is happening to you...You know…You can feel it…

The voice hissed and slithered through his head, and Percy trembled-but not because it felt wrong. Because it felt right. Far too right. As though this voice had always been a part of him…as though it was meant to be there. As though he was meant to be listening to it.

He clenched his fists, gritted his teeth-

"No," he hissed, every muscle tightening. "No…"

Yes…You know, little hero…

Percy leapt to his feet, Riptide springing outwards, glowing in his hands. Anger was scalding through him, pounding so forcefully within his head that he couldn't stop himself-couldn't stop himself from reaching out, slashing the bunk bed nearest him in half. It exploded, fragments of it ricocheting around the cabin, collapsing with a thunderous crash. Part of him screamed-he hadn't meant to do that, he didn't want to do that, how had he done that, he wasn't that strong-but the anger was overwhelming him, edging his vision with red, obliterating all other thoughts.

"Tartarus," he screamed-but it didn't sound like his voice, and he hadn't meant to yell... "Show yourself!"

Oh, you can see me easily enough. The voice was amused. Just look at your own hands, little hero…

Percy didn't want to. He didn't mean to. But his neck bent, against his will, until he was staring down at his hands. They were trembling, bathed in Riptide's bronze glow-covered in the sawdust of the bed he had smashed.

Do you understand yet?

The anger was gone-far too quickly, far too completely. There was nothing left but a hollow emptiness. He tried to speak-to whisper the word no-but his lips were no longer his own.

Yes, you understand now. Far too late…But now…Now you will acknowledge your liege…

He cannot make me, Percy thought-he tried to grit his teeth, to clench his fists, to force himself free. I have a choice, he whispered to himself. He cannot do this to me…

Oh, I can. You still don't understand…You are not who you think you are…

His heart should have been thundering. He should have been fighting. He should have been running, finding someone to help him, to break him free of this. He should have been overcoming it. He was a demigod. He was a hero. He was stronger than this…

You are not…You are not a hero…You are mine...

He could not speak. Could not move. But still, his hands were loose at his side, holding Riptide as easily as though it were a feather, his heart was beating as steadily as if he was sleeping, his muscles relaxed…

Listen to me…You are mine…Why would you want to be a godling anyway? Like they care about you…Like you are anything more than a tool for them…A toy for their every whim…

Percy tried to tell himself not to listen. But the voice was starting to sound more and more like his own-and these were thoughts that he knew all too well. He tried to remind himself who he was talking to. What he was doing to him. That Tartarus was far worse than the gods could ever be…

Am I really? I will not lie to you…I will not cast you aside…My servants are rewarded…I grant them immortality…I know every one…The name of every telkhine, every Laestrygonian, every arai…And for you I offer power…You would be the leader of my forces…Honored…You would choose your actions…

His head pounded-his heart barely beat. There was a reason he should refuse. There were so many reasons. The world…The world would burn under Tartarus. His friends…his family…they would be dead…

But would you give that? To finally be free? To be more than a pawn…a tool…What would you give, Perseus Jackson?

Something deep inside of him cried out, and rose up, and swallowed him, and it felt dark and sharp and dangerous, and for a moment he fought-but he couldn't keep fighting, because it felt so right. It felt like freedom.

What would he give for that? What would he give to finally be in control? He would give everything. Everything.

I would give everything, he whispered. I would burn the world down myself.

Then you are mine.

And, in a way, it was Percy Jackson who knelt, who laid his sword down on the ground, who pressed his bent knees against the floor, who let his hands and his head fall downwards, bowing to an invisible god who was all around him.

But in another way, it was not Percy Jackson at all who did these things-not him, but the being of darkness that Tartarus had spun him into, building more and more of his own spirit into the demigod's, connected by the time that he had spent walking across Tartarus' body and drinking his blood to keep himself alive.

Not Percy Jackson at all.