The Last Olympian

a room paneled with abalone shell. Glowing pearls the size of basketballs floated around the ceiling, providing light. I was under water.
    Now, being the son of Poseidon and all, I was okay with this. I can breathe underwater just fine, and my clothes don’t even get wet unless I want them to. But it was still a bit of a shock when a hammerhead shark drifted through the bedroom window, regarded me, and then swam calmly out the opposite side of the room.
    “Where—”
    “Daddy’s palace,” Tyson said.
    Under different circumstances, I would’ve been excited. I’d never visited Poseidon’s realm, and I’d been dreaming about it for years. But my head hurt. My shirt was still speckled with burn marks from the explosion. My arm and leg wounds had healed—just being in the ocean can do that for me, given enough time—but I still felt like I’d been trampled by a Laistrygonian soccer team in cleats.
    “How long—”
    “We found you last night,” Tyson said, “sinking through the water.”
    “The Princess Andromeda ?”
    “Went ka-boom,” Tyson confirmed.
    “Beckendorf was on board. Did you find . . .”
    Tyson’s face darkened. “No sign of him. I am sorry, brother.”
    I stared out the window into deep blue water. Beckendorf was supposed to go to college in the fall. He had a girlfriend, lots of friends, his whole life ahead of him. He couldn’t be gone . Maybe he’d made it off the ship like I had. Maybe he’d jumped over the side . . . and what? He couldn’t have survived a hundred-foot fall into the water like I could. He couldn’t have put enough distance between himself and the explosion.
    I knew in my gut he was dead. He’d sacrificed himself to take out the Princess Andromeda , and I had abandoned him.
    I thought about my dream: the Titans discussing the explosion as if it didn’t matter, Nico di Angelo warning me that I would never beat Kronos without following his plan—a dangerous idea I’d been avoiding for more than a year.
    A distant blast shook the room. Green light blazed outside, turning the whole sea as bright as noon.
    “What was that?” I asked.
    Tyson looked worried. “Daddy will explain. Come, he is blowing up monsters.”
    The palace might have been the most amazing place I’d ever seen if it hadn’t been in the process of getting destroyed. We swam to the end of a long hallway and shot upward on a geyser. As we rose over the rooftops I caught my breath— well, if you can catch your breath underwater.
    The palace was as big as the city on Mount Olympus, with wide courtyards, gardens, and columned pavilions. The gardens were sculpted with coral colonies and glowing sea plants. Twenty or thirty buildings were made of abalone, white but gleaming with rainbow colors. Fish and octopi darted in and out of the windows. The paths were lined with glowing pearls like Christmas lights.
    The main courtyard was filled with warriors—mermen with fish tails from the waist down and human bodies from the waist up, except their skin was blue, which I’d never known before. Some were tending the wounded. Some were sharpening spears and swords. One passed us, swimming in a hurry. His eyes were bright green, like that stuff they put in glo-sticks, and his teeth were shark teeth. They don’t show you stuff like that in The Little Mermaid .
    Outside the main courtyard stood large fortifications— towers, walls, and antisiege weapons—but most of these had been smashed to ruins. Others were blazing with a strange green light that I knew well—Greek fire, which can burn even underwater.
    Beyond this, the sea floor stretched into gloom. I could see battles raging—flashes of energy, explosions, the glint of armies clashing. A regular human would’ve found it too dark to see. Heck, a regular human would’ve been crushed by the pressure and frozen by the cold. Even my heat-sensitive eyes couldn’t make out exactly what was going on.
    At the edge of the palace complex, a temple with a red coral roof exploded, sending fire and debris streaming in slow motion across the farthest gardens. Out of the darkness above, an enormous form appeared—a squid larger than any skyscraper. It was surrounded by a glittering cloud of dust—at least I thought it was dust until I realized it was a swarm of mermen trying to attack the monster. The squid descended on the palace, swatted its tentacles, smashing whole columns of warriors. Then a brilliant arc of blue light shot from the rooftop of one