I steered Grover and Annabeth toward the exit, loaded them into the elevator, and I was about to get in myself when I realized there were already two other tourists inside. No room for me.

The park ranger said, "Next car, sir."

"We'll get out," Annabeth said. "We'll wait with you."

But that was going to mess everybody up and take even more time, so I said, "Naw, it's okay. I'll see you guys at the bottom."

Grover and Annabeth both looked nervous, but they let the elevator door slide shut. Their car disappeared down the ramp.

Now the only people left on the observation deck were me, a little boy with his parents, the park ranger, and the fat lady with her Chihuahua.

I smiled uneasily at the fat lady. She smiled back, her forked tongue flickering between her teeth.

Wait a minute.

Forked tongue?

Before I could decide if I'd really seen that, her Chihuahua jumped down and started yapping at me.

"Now, now, sonny," the lady said. "Does this look like a good time? We have all these nice people here."

"Doggie!" said the little boy. "Look, a doggie!"

His parents pulled him back.

The Chihuahua bared his teeth at me, foam dripping from his black lips.

"Well, son," the fat lady sighed. "If you insist."

Ice started forming in my stomach. "Urn, did you just call that Chihuahua your son?"

"Chimera, dear," the fat lady corrected. "Not a Chihuahua. It's an easy mistake to make."

She rolled up her denim sleeves, revealing that the skin of her arms was scaly and green. When she smiled, I saw that her teeth were fangs. The pupils of her eyes were sideways slits, like a reptile's.

The Chihuahua barked louder, and with each bark, it grew. First to the size of a Doberman, then to a lion. The bark became a roar.

The little boy screamed. His parents pulled him back toward the exit, straight into the park ranger, who stood, paralyzed, gaping at the monster.

The Chimera was now so tall its back rubbed against the roof. It had the head of a lion with a blood-caked mane, the body and hooves of a giant goat, and a serpent for a tail, a ten-foot-long diamondback growing right out of its shaggy behind. The rhinestone dog collar still hung around its neck, and the plate-sized dog tag was now easy to read: CHIMERA—RABID, FIRE-BREATHING, POISONOUS—IF FOUND, PLEASE CALL TARTARUS—EXT. 954.

I realized I hadn't even uncapped my sword. My hands were numb. I was ten feet away from the Chimera's bloody maw, and I knew that as soon as I moved, the creature would lunge.

The snake lady made a hissing noise that might've been laughter. "Be honored, Percy Jackson. Lord Zeus rarely allows me to test a hero with one of my brood. For I am the Mother of Monsters, the terrible Echidna!"

I stared at her. All I could think to say was: "Isn't that a kind of anteater?"

She howled, her reptilian face turning brown and green with rage. "I hate it when people say that! I hate Australia! Naming that ridiculous animal after me. For that, Percy Jackson, my son shall destroy you!"

The Chimera charged, its lion teeth gnashing. I managed to leap aside and dodge the bite.

I ended up next to the family and the park ranger, who were all screaming now, trying to pry open the emergency exit doors.

I couldn't let them get hurt. I uncapped my sword, ran to the other side of the deck, and yelled, "Hey, Chihuahua!" The Chimera turned faster than I would've thought possible.

Before I could swing my sword, it opened its mouth, emitting a stench like the world's largest barbecue pit, and shot a column of flame straight at me.

I dove through the explosion. The carpet burst into flames; the heat was so intense, it nearly seared off my eyebrows.

Where I had been standing a moment before was a ragged hole in the side of the Arch, with melted metal steaming around the edges.

Great, I thought. We just blowtorched a national monument.

Riptide was now a shining bronze blade in my hands, and as the Chimera turned, I slashed at its neck.

That was my fatal mistake. The blade sparked harmlessly off the dog collar. I tried to regain my balance, but I was so worried about defending myself against the fiery lion's mouth, I completely forgot about the serpent tail until it whipped around and sank its fangs into my calf.

My whole leg was on fire. I tried to jab Riptide into the Chimera's mouth, but the serpent tail wrapped around my ankles and pulled me off balance, and my blade flew out of my hand, spinning out of the hole in the Arch and down toward the Mississippi River.

I managed to get to my feet, but I knew I had lost. I was weaponless. I could feel deadly poison racing up to my chest. I remembered Chiron saying that Anaklusmos would always return to me, but there was no pen in my pocket. Maybe it had fallen too far away. Maybe it only returned when it was in pen form. I didn't know, and I wasn't going to live long enough to figure it out.

I backed into the hole in the wall. The Chimera advanced, growling, smoke curling from its lips. The snake lady, Echidna, cackled. "They don't make heroes like they used to, eh, son?"

The monster growled. It seemed in no hurry to finish me off now that I was beaten.

I glanced at the park ranger and the family. The little boy was hiding behind his father's legs. I had to protect these people. I couldn't just ... die. I tried to think, but my whole body was on fire. My head felt dizzy. I had no sword. I was facing a massive, fire-breathing monster and its mother. And I was scared.

There was no place else to go, so I stepped to the edge of the hole. Far, far below, the river glittered.

If I died, would the monsters go away? Would they leave the humans alone?

"If you are the son of Poseidon," Echidna hissed, "you would not fear water. Jump, Percy Jackson. Show me that water will not harm you. Jump and retrieve your sword. Prove your bloodline."

Yeah, right, I thought. I'd read somewhere that jumping into water from a couple of stories up was like jumping onto solid asphalt. From here, I'd splatter on impact.

The Chimera's mouth glowed red, heating up for another blast.

"You have no faith," Echidna told me. "You do not trust the gods. I cannot blame you, little coward. Better you die now. The gods are faithless. The poison is in your heart."

She was right: I was dying. I could feel my breath slowing down. Nobody could save me, not even the gods.

I backed up and looked down at the water. I remembered the warm glow of my father's smile when I was a baby. He must have seen me. He must have visited me when I was in my cradle.

I remembered the swirling green trident that had appeared above my head the night of capture the flag, when Poseidon had claimed me as his son.

But this wasn't the sea. This was the Mississippi, dead center of the USA. There was no Sea God here.

"Die, faithless one," Echidna rasped, and the Chimera sent a column of flame toward my face.

"Father, help me," I prayed.

I turned and jumped. My clothes on fire, poison coursing through my veins, I plummeted toward the river.

14. I BECOME A KNOWN FUGITIVE

I'd love to tell you I had some deep revelation on my way down, that I came to terms with my own mortality, laughed in the face of death, et cetera.

The truth? My only thought was: Aaaaggghhhhh!

The river raced toward me at the speed of a truck. Wind ripped the breath from my lungs. Steeples and skyscrapers and bridges tumbled in and out of my vision.

And then: Flaaa-boooom!

A whiteout of bubbles. I sank through the murk, sure that I was about to end up embedded in a hundred feet of mud and lost forever.

But my impact with the water hadn't hurt. I was falling slowly now, bubbles trickling up through my fingers. I settled on the river bottom soundlessly. A catfish the size of my stepfather lurched away into the gloom. Clouds of silt and disgusting garbage—beer bottles, old shoes, plastic bags—swirled up all around me.

At that point, I realized a few things: first, I had not been flattened into a pancake. I had not been barbecued. I couldn't even feel the Chimera poison boiling in my veins anymore. I was alive, which was good.

Second realization: I wasn't wet. I mean, I could feel the coolness of the water. I could see where the fire on my clothes had been quenched. But when I touched my own shirt, it felt perfectly dry.

I looked at the garbage floating by and snatched an old cigarette lighter.

No way, I thought.

I flicked the lighter. It sparked. A tiny flame appeared, right there at the bottom of the Mississippi.

I grabbed a soggy hamburger wrapper out of the current and immediately the paper turned dry. I lit it with no problem. As soon as I let it go, the flames sputtered out. The wrapper turned back into a slimy rag. Weird.

But the strangest thought occurred to me only last: I was breathing. I was underwater, and I was breathing normally.

I stood up, thigh-deep in mud. My legs felt shaky. My hands trembled. I should've been dead. The fact that I wasn't seemed like ... well, a miracle. I imagined a woman's voice, a voice that sounded a bit like my mother: Percy, what do you say?

"Um ... thanks." Underwater, I sounded like I did on recordings, like a much older kid. "Thank you ... Father."

No response. Just the dark drift of garbage downriver, the enormous catfish gliding by, the flash of sunset on the water's surface far above, turning everything the color of butterscotch.

Why had Poseidon saved me? The more I thought about it, the more ashamed I felt. So I'd gotten lucky a few times before. Against a thing like the Chimera, I had never stood a chance. Those poor people in the Arch were probably toast. I couldn't protect them. I was no hero. Maybe I should just stay down here with the catfish, join the bottom feeders.

Fump-fump-fump. A riverboat's paddlewheel churned above me, swirling the silt around.

There, not five feet in front of me, was my sword, its gleaming bronze hilt sticking up in the mud.

I heard that woman's voice again: Percy, take the sword. Your father believes in you. This time, I knew the voice wasn't in my head. I wasn't imagining it. Her words seemed to come from everywhere, rippling through the water like dolphin sonar.

"Where are you?" I called aloud.

Then, through the gloom, I saw her—a woman the color of the water, a ghost in the current, floating just above the sword. She had long billowing hair, and her eyes, barely visible, were green like mine.

A lump formed in my throat. I said, "Mom?"

No, child, only a messenger, though your mother's fate is not as hopeless as you believe. Go to the beach in Santa Monica.

"What?"

It is your father's will. Before you descend into the Underworld, you must go to Santa Monica. Please, Percy, I cannot stay long. The river here is too foul for my presence.

"But ..." I was sure this woman was my mother, or a vision of her, anyway. "Who—how did you—"

There was so much I wanted to ask, the words jammed up in my throat.

I cannot stay, brave one, the woman said. She reached out, and I felt the current brush my face like a caress. You must go to Santa Monica! And, Percy, do not trust the gifts....

Her voice faded.

"Gifts?" I asked. "What gifts? Wait!"

She made one more attempt to speak, but the sound was gone. Her image melted away. If it was my mother, I had lost her again.

I felt like drowning myself. The only problem: I was immune to drowning.