The Lightning Thief

demigod, you can be killed by either celestial or normal weapons. You are twice as vulnerable.”
    “Good to know.”
    “Now recap the pen.”
    I touched the pen cap to the sword tip and instantly Riptide shrank to a ballpoint pen again. I tucked it in my pocket, a little nervous, because I was famous for losing pens at school.
    “You can’t,” Chiron said.
    “Can’t what?”
    “Lose the pen,” he said. “It is enchanted. It will always reappear in your pocket. Try it.”
    I was wary, but I threw the pen as far as I could down the hill and watched it disappear in the grass.
    “It may take a few moments,” Chiron told me. “Now check your pocket.”
    Sure enough, the pen was there.
    “Okay, that’s extremely cool,” I admitted. “But what if a mortal sees me pulling out a sword?”
    Chiron smiled. “Mist is a powerful thing, Percy.”
    “Mist?”
    “Yes. Read The Iliad . It’s full of references to the stuff. Whenever divine or monstrous elements mix with the mortal world, they generate Mist, which obscures the vision of humans. You will see things just as they are, being a half-blood, but humans will interpret things quite differently. Remarkable, really, the lengths to which humans will go to fit things into their version of reality.”
    I put Riptide back in my pocket.
    For the first time, the quest felt real. I was actually leaving Half-Blood Hill. I was heading west with no adult supervision, no backup plan, not even a cell phone. (Chiron said cell phones were traceable by monsters; if we used one, it would be worse than sending up a flare.) I had no weapon stronger than a sword to fight off monsters and reach the Land of the Dead.
    “Chiron . . .” I said. “When you say the gods are immortal . . . I mean, there was a time before them, right?”
    “Four ages before them, actually. The Time of the Titans was the Fourth Age, sometimes called the Golden Age, which is definitely a misnomer. This, the time of Western civilization and the rule of Zeus, is the Fifth Age.”
    “So what was it like . . . before the gods?”
    Chiron pursed his lips. “Even I am not old enough to remember that, child, but I know it was a time of darkness and savagery for mortals. Kronos, the lord of the Titans, called his reign the Golden Age because men lived innocent and free of all knowledge. But that was mere propaganda. The Titan king cared nothing for your kind except as appetizers or a source of cheap entertainment. It was only in the early reign of Lord Zeus, when Prometheus the good Titan brought fire to mankind, that your species began to progress, and even then Prometheus was branded a radical thinker. Zeus punished him severely, as you may recall. Of course, eventually the gods warmed to humans, and Western civilization was born.”
    “But the gods can’t die now, right? I mean, as long as Western civilization is alive, they’re alive. So . . . even if I failed, nothing could happen so bad it would mess up every thing , right?”
    Chiron gave me a melancholy smile. “No one knows how long the Age of the West will last, Percy. The gods are immortal, yes. But then, so were the Titans. They still exist, locked away in their various prisons, forced to endure endless pain and punishment, reduced in power, but still very much alive. May the Fates forbid that the gods should ever suffer such a doom, or that we should ever return to the darkness and chaos of the past. All we can do, child, is follow our destiny.”
    “Our destiny . . . assuming we know what that is.”
    “Relax,” Chiron told me. “Keep a clear head. And remember, you may be about to prevent the biggest war in human history.”
    “Relax,” I said. “I’m very relaxed.”
    When I got to the bottom of the hill, I looked back. Under the pine tree that used to be Thalia, daughter of Zeus, Chiron was now standing in full horse-man form, holding his bow high in salute. Just your typical summer-camp send-off by your typical centaur.
    * * *
    Argus drove us out of the countryside and into western Long Island. It felt weird to be on a highway again, Annabeth and Grover sitting next to me as if we were normal carpoolers. After two weeks at Half-Blood Hill, the real world seemed like a fantasy. I found myself staring at every McDonald’s, every kid in the back of his parents’ car, every billboard and shopping mall.
    “So far so good,” I told Annabeth. “Ten miles and not a single monster.”
    She gave me an irritated look. “It’s