The Last Olympian

a second I thought he was Ares, because this guy looked exactly like the god of war—tall and buff, with a cruel 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 spoke with Luke?”
    “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, 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 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 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.”
    “I don’t suppose you could tell me Luke’s mortal point?”
    He scowled. “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 didn’t look pleased about that, but I didn’t care.
    Before I could change my mind, I concentrated on the small of my back—a tiny point just opposite my navel. It was well defended when I wore my armor. 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 small of my back. And I stepped into the river.
    Imagine jumping into a pit of boiling acid. Now multiply that pain times fifty. 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.
    I was losing the fight. The pain was too much. My hands and feet were melting into the water, my soul was being ripped from my body. I couldn’t remember who I was. The pain of Kronos’s scythe had been nothing compared to this.
    The cord , a familiar voice said. Remember your lifeline, dummy!
    Suddenly 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.
    “Hold on, Seaweed