Nico and I were standing at the edge of the River Styx, and I was staring at it apprehensively. 

The River Styx's current swirled with strange objects—broken toys, ripped-up college diplomas, wilted homecoming corsages: all the dreams people had thrown away as they'd passed from life into death.

Looking at the black water, I could think of about three million places I'd rather swim.

"So . . . I just jump in?" I ignored the bad feeling I had about this whole thing.

"You have to prepare yourself first," Nico said, "or the river will destroy you. It will burn away your body and soul."

 "Ooh, I just love it when my body and soul burns away" I muttered.

 "This is no joke," Nico warned. "There is only one way to stay anchored to your mortal life. You have to . . ."

  He glanced behind me and his eyes widened. I turned and found myself face-to-face with a Greek warrior.

 For a second I thought he was Ares, because this guy looked exactly like the god of war—tall and buff, with a scarred face and closely shaved black hair. He wore a white tunic and bronze armor. 

He held a plumed war helm under his arm. But his eyes were human—pale green like a shallow sea—and a bloody arrow stuck out of his left calf, just above the ankle.

 I stunk at Greek names, but even I knew the greatest warrior of all time, who had died from a wounded heel.

 "Achilles," I said.

 The ghost nodded. "I warned the other one not to follow my path. Now I will warn you."

 "Luke? You saw Luke? What did he do?"

 Achilles ignored his questions. "Do not do this," he said. "It will make you powerful. But it will also make you weak. Your prowess in combat will be beyond any mortal's, but your weaknesses, your failings will increase as well."

 "You mean I'll have a bad heel?" I said. "Couldn't I just, like, wear something besides sandals? No offense."

 He stared down at his bloody foot. "The heel is only my physical weakness, demigod. My mother, Thetis, held me there when she dipped me in the Styx. What really killed me was my own arrogance. Beware! Turn back!"

 He meant it. I could hear the regret and bitterness in his voice. He was honestly trying to save me from a terrible fate.

 Then again, Luke had been here, and he hadn't turned back.

 That's why Luke had been able to host the spirit of Kronos without his body disintegrating. 

This is how he'd prepared himself, and why he seemed impossible to kill. He had bathed in the River Styx and taken on the powers of the greatest mortal hero, Achilles. 

He was invincible.

"I have to," I said. "Otherwise I don't stand a chance."

Achilles lowered his head. "Let the gods  witness that I tried. Hero, if you must do this, concentrate on your mortal point. Imagine one spot of your body that will remain vulnerable. This is the point where your soul will anchor your body to the world. It will be your greatest weakness, but also your only hope. No mortal man may be completely invulnerable. Lose sight of what keeps you mortal, and the River Styx will burn you to ashes. You will cease to exist. You will be obliterated, wiped from existence-"

Stolen from its rightful place, this narrative is not meant to be on Amazon; report any sightings.

"I don't suppose you could tell me Luke's mortal point?”

 He scowled at the interruption. "Prepare yourself, foolish boy. Whether you survive this or not, you have sealed your doom!"

With that happy thought, he vanished.

"Percy," Nico said, "maybe he's right."

"This was your idea."

"I know, but now that we're here—"

"Just wait on the shore. If anything happens to me . . . Well, maybe Hades will get his wish, and you'll be the child of the prophecy after all."

He paled, looking both terrified and apprehensive at the idea.

Before I could change my mind, I concentrated on small of my back. It would be hard to hit by accident, and few enemies would aim for it on purpose. No place was perfect, but this seemed right to me, and a lot more dignified than, like, my armpit or something. 

I pictured a string, a bungee cord connecting me to the world from the spot on my back. And I stepped into the river.

Imagine jumping into a pit of boiling acid. Now multiply that pain times a hundred. You still won't be close to understanding what it felt like to swim in the Styx.

I planned to walk in slow and courageous like a real hero. As soon as the water touched my legs, my muscles turned to jelly and I fell face-first into the current. I submerged completely. 

 For the first time in my life, I couldn't breathe underwater. I finally understood the panic of drowning. Every nerve in my body burned. I was dissolving in the water. 

I saw faces—Rachel, Grover, Tyson, my mother—but they faded as soon as they appeared.

 "Percy," my mom said. "I give you my blessing."

"Be safe, brother!" Tyson pleaded.

"Enchiladas!"Grover said. I wasn't sure where that came from, but it didn't seem to help much. Or at all, really.

I felt my soul burning away, and I panicked. My lungs ached and my eyes burned from keeping them open for so long in the Styx. I looked down slightly at my body, and saw my legs and arms literally fading. That was the last thing I saw, before my vision went black and my soul burned away.

~PJO~

I woke up feeling like I was on fire. I immediately opened my eyes and then closed them again.

Owww! My eyes burned like hell. 

So of course I immediately opened them again. It still burned a lot, but I ignored it and looked around. Everything looked blurry, but I could make out some stuff. I was surrounded by what looked like water? That was weird. And painful.

I tried to move and found I couldn't. I panicked and tried to yell, bubbles streaming out of my mouth.

I was burning up! Someone help me! Oh gods, how did I get here? Did I die in my sleep and end up in hell? 

No that couldn't be it. I tried to think of any possible way that I could have gotten in some water that literally felt like it was burning the flesh off my bones. It was hard to concentrate, but I managed to come up with this:

1) I had somehow sleepwalked into some kind of hot spring? That was stupid, because I didn't even live near any.

2) This was a nightmare, and I would wake up any second now.

3) I had been kidnapped by sadistic aliens who were intent on torturing me to insanity. (Yes, I believe in magic and paranormal stuff and aliens. It just... makes sense.)

4) I had been transported into the body of either Luke Castellan or Percy Jackson at the same time they were bathing in the River Styx.

Ok, that last one seemed a little far-fetched, but let me explain the thought process behind all of these. First of all, I do not sleepwalk, so that was off the list.

Second of all, I also didn't think a nightmare would be this realistic, or painful. Or I would have definitely woken up by now.

Third of all, I mean, I could have been kidnapped by aliens, but to be honest, who tries to torture someone without telling them they're doing it first? That would ruin the point. So that one was off the table. 

And finally, I couldn't really think of anything other than the Percy Jackson series where there was a river that burned you. And burned away your soul. Which made sense, since, if either Luke or Percy were in the Styx, their soul could have just burned away, and I could have been transported into their body instead...

I thought of all that within five seconds. Yes, my brain works super fast. I was (Supposedly) a genius. 

So, I guess this could just be a nightmare. But just in case, I did what I was supposed to do to survive in Percy Jackson. I focused on memories of my life, of my little sister, Angelica, who was the sweetest little creature to ever exist. I focused on my best friend, Lucas Gloss, and how he cheered me on from the sidelines whenever I made a basket in basketball. I focused on my crush, Katie Wallace, and how she smiled at me whenever I talked to her. I thought of a whole bunch of memories, and then imagined them forming a rope, sort of like a bungee cord, tied to the small of my back, and then grounded to the world above.

It worked.

I felt myself becoming solid, or at least, more me. My lungs stopped hurting as much and there was a tug in my lower back. The current pulled at me, but it wasn't carrying me away anymore. I imagined the string in my back keeping me tied to the shore.  The cord strengthened as I continued to think of my past life. I saw an apparition of my crush Katie floating in front of me. She was smiling as she held out a hand to me. "You are such an idiot. Come on. Take my hand."

Memories came flooding back to me—sharper and more colorful. I stopped dissolving. I reached up and took Katie's hand.

Suddenly I burst out of the river. I collapsed on the sand, and a black-haired boy scrambled back in surprise.

"Are you okay?" he stammered. "Your skin. Oh, gods. You're hurt!"

My arms and legs were bright red. I felt like every inch of my body had been broiled over a slow flame. 

I looked around for Katie, though I knew she wasn't here. It had seemed so real.

"Y-yeah, I'm fine." I stammered. Then I flushed. I had no idea how to act like Percy Jackson!  

I looked up. The boy in front of me had shaggy, messy black hair, olive skin and dark brown eyes. This was Nico di Angelo.

 Now I knew for sure I had somehow been transported into Percy Jackson. I was amazed and terrified at the same time. Why me? I couldn't exactly do anything special. I was just an annoying genius, who had read the Percy Jackson books before. I was just Alexander Aldane. I was a nobody.

"Do you feel any stronger?" Nico asked.

 Before I could decide what I felt, a voice boomed, "THERE!"

An army of the dead marched toward us. A hundred skeletal Roman legionnaires led the way with shields and spears. Behind them came an equal number of British redcoats with bayonets fixed. In the middle of the host, Hades himself rode a black-and-gold chariot pulled by nightmare horses, their eyes and manes smoldering with fire.

"You will not escape me this time, Percy Jackson!" Hades bellowed. "Destroy him!"

 "Father, no!" Nico shouted, but it was too late. The front line of Roman zombies lowered their spears and advanced.