Dead Confederates rushed back and forth. The propeller grinded into reverse, trying to slow the ship, but we kept sliding toward the center of the vortex.

A zombie sailor burst out of the hold and ran to Clarisse. His gray uniform was smoking. His beard was on fire. "Boiler room overheating, ma'am! She's going to blow!"

"Well, get down there and fix it!"

"Can't!" the sailor yelled. "We're vaporizing in the heat."

Clarisse pounded the side of the casemate. "All I need is a few more minutes! Just enough to get in range!"

"We're going in too fast," the captain said grimly. "Prepare yourself for death."

"No!" Tyson bellowed. "I can fix it."

Clarisse looked at him incredulously. "You?"

"He's a Cyclops," Annabeth said. "He's immune to fire. And he knows mechanics."

"Go!" yelled Clarisse.

"Tyson, no!" I grabbed his arm. "It's too dangerous!"

He patted my hand. "Only way, brother." His expression was determined—confident, even. I'd never seen him look like this before. "I will fix it. Be right back."

As I watched him follow the smoldering sailor down the hatch, I had a terrible feeling. I wanted to run after him, but the ship lurched again—and then I saw Charybdis.

She appeared only a few hundred yards away, through a swirl of mist and smoke and water. The first thing I noticed was the reef—a black crag of coral with a fig tree clinging to the top, an oddly peaceful thing in the middle of a maelstrom. All around it, water curved into a funnel, like light around a black hole. Then I saw the horrible thing anchored to the reef just below the waterline—an enormous mouth with slimy lips and mossy teeth the size of rowboats. And worse, the teeth had braces, bands of corroded scummy metal with pieces of fish and driftwood and floating garbage stuck between them.

Charybdis was an orthodontist's nightmare. She was nothing but a huge black maw with bad teeth alignment and a serious overbite, and she'd done nothing for centuries but eat without brushing after meals. As I watched, the entire sea around her was sucked into the void—sharks, schools of fish, a giant squid. And I realized that in a few seconds, the CSS Birmingham would be next.

"Lady Clarisse," the captain shouted. "Starboard and forward guns are in range!"

"Fire!" Clarisse ordered.

Three rounds were blasted into the monster's maw. One blew off the edge of an incisor. Another disappeared into her gullet. The third hit one of Charybdis's retaining bands and shot back at us, snapping the Ares flag off its pole.

"Again!" Clarisse ordered. The gunners reloaded, but I knew it was hopeless. We would have to pound the monster a hundred more times to do any real damage, and we didn't have that long. We were being sucked in too fast.

Then the vibrations in the deck changed. The hum of the engine got stronger and steadier. The ship shuddered and we started pulling away from the mouth.

"Tyson did it!" Annabeth said.

"Wait!" Clarisse said. "We need to stay close!"

"We'll die!" I said. "We have to move away."

I gripped the rail as the ship fought against the suction. The broken Ares flag raced past us and lodged in Charybdis's braces. We weren't making much progress, but at least we were holding our own. Tyson had somehow given us just enough juice to keep the ship from being sucked in.

Suddenly, the mouth snapped shut. The sea died to absolute calm. Water washed over Charybdis.

Then, just as quickly as it had closed, the mouth exploded open, spitting out a wall of water, ejecting everything inedible, including our cannonballs, one of which slammed into the side of the CSS Birmingham with a ding like the bell on a carnival game.

We were thrown backward on a wave that must've been forty feet high. I used all of my willpower to keep the ship from capsizing, but we were still spinning out of control, hurtling toward the cliffs on the opposite side of the strait.

Another smoldering sailor burst out of the hold. He stumbled into Clarisse, almost knocking them both overboard. "The engine is about to blow!"

"Where's Tyson?" I demanded.

"Still down there," the sailor said. "Holding it together somehow, though I don't know for how much longer."

The captain said, "We have to abandon ship."

"No!" Clarisse yelled.

"We have no choice, m'lady. The hull is already cracking apart! She can't—"

He never finished his sentence. Quick as lightning, something brown and green shot from the sky, snatched up the captain, and lifted him away. All that was left were his leather boots.

"Scylla!" a sailor yelled, as another column of reptilian flesh shot from the cliffs and snapped him up. It happened so fast it was like watching a laser beam rather than a monster. I couldn't even make out the thing's face, just a flash of teeth and scales.

I uncapped Riptide and tried to swipe at the monster as it carried off another deckhand, but I was way too slow.

"Everyone get below!" I yelled.

"We can't!" Clarisse drew her own sword. "Below deck is in flames."

"Lifeboats!" Annabeth said. "Quick!"

"They'll never get clear of the cliffs," Clarisse said. "We'll all be eaten."

"We have to try. Percy, the thermos."

"I can't leave Tyson!"

"We have to get the boats ready!"

Clarisse took Annabeth's command. She and a few of her undead sailors uncovered one of the two emergency rowboats while Scylla's heads rained from the sky like a meteor shower with teeth, picking off Confederate sailors one after another.

"Get the other boat." I threw Annabeth the thermos. "I'll get Tyson."

"You can't!" she said. "The heat will kill you!"

I didn't listen. I ran for the boiler room hatch, when suddenly my feet weren't touching the deck anymore. I was flying straight up, the wind whistling in my ears, the side of the cliff only inches from my face.

Scylla had somehow caught me by the knapsack, and was lifting me up toward her lair. Without thinking, I swung my sword behind me and managed to jab the thing in her beady yellow eye. She grunted and dropped me.

The fall would've been bad enough, considering I was a hundred feet in the air. But as I fell, the CSS Birmingham exploded below me.

KAROOM!

The engine room blew, sending chunks of ironclad flying in either direction like a fiery set of wings.

"Tyson!" I yelled.

The lifeboats had managed to get away from the ship, but not very far. Flaming wreckage was raining down. Clarisse and Annabeth would either be smashed or burned or pulled to the bottom by the force of the sinking hull, and that was thinking optimistically, assuming they got away from Scylla.

Then I heard a different kind of explosion—the sound of Hermes's magic thermos being opened a little too far. White sheets of wind blasted in every direction, scattering the lifeboats, lifting me out of my free fall and propelling me across the ocean.

I couldn't see anything. I spun in the air, got clonked on the head by something hard, and hit the water with a crash that would've broken every bone in my body if I hadn't been the son of the Sea God.

The last thing I remembered was sinking in a burning sea, knowing that Tyson was gone forever, and wishing I were able to drown.