In the distance, the conch horn sounded, signaling curfew.

“You should get to bed,” Hermes said. “I’ve helped you get into quite enough trouble this summer already. I really only came to make this delivery.”

“A delivery?”

“I am the messenger of the gods, Percy.” He took an electronic signature pad from his mailbag and handed it to me. “Sign there, please.”

I picked up the stylus before realizing it was entwined with a pair of tiny green snakes. “Ah!” I dropped the pad.

Ouch, said George.

Really, Percy, Martha scolded. Would you want to be dropped on the floor of a horse stable?

“Oh, uh, sorry.” I didn’t much like touching snakes, but I picked up the pad and the stylus again. Martha and George wriggled under my fingers, forming a kind of pencil grip like the ones my special ed teacher made me use in second grade.

Did you bring me a rat? George asked.

“No …” I said. “Uh, we didn’t find any.”

What about a guinea pig?

George! Martha chided. Don’t tease the boy.

I signed my name and gave the pad back to Hermes.

In exchange, he handed me a sea-blue envelope.

My fingers trembled. Even before I opened it, I could tell it was from my father. I could sense his power in the cool blue paper, as if the envelope itself had been folded out of an ocean wave.

“Good luck tomorrow,” Hermes said. “Fine team of horses you have there, though you’ll excuse me if I root for the Hermes cabin.”

And don’t be too discouraged when you read it, dear, Martha told me. He does have your interests at heart.

“What do you mean?” I asked.

Don’t mind her, George said. And next time, remember, snakes work for tips.

“Enough, you two,” Hermes said. “Good-bye, Percy. For now.”

Small white wings sprouted from his pith helmet. He began to glow, and I knew enough about the gods to avert my eyes before he revealed his true divine form. With a brilliant white flash he was gone, and I was alone with the horses.

I stared at the blue envelope in my hands. It was addressed in strong but elegant handwriting that I’d seen once before, on a package Poseidon had sent me last summer.

Percy Jackson

c/o Camp Half-Blood

Farm Road 3.141

Long Island, New York 11954

An actual letter from my father. Maybe he would tell me I’d done a good job getting the Fleece. He’d explain about Tyson, or apologize for not talking to me sooner. There were so many things that I wanted that letter to say.

I opened the envelope and unfolded the paper.

Two simple words were printed in the middle of the page:

Brace Yourself

The next morning, everybody was buzzing about the chariot race, though they kept glancing nervously toward the sky like they expected to see Stymphalian birds gathering. None did. It was a beautiful summer day with blue sky and plenty of sunshine. The camp had started to look the way it should look: the meadows were green and lush; the white columns gleamed on the Greek buildings; dryads played happily in the woods.

And I was miserable. I’d been lying awake all night, thinking about Poseidon’s warning.

Brace yourself.

I mean, he goes to the trouble of writing a letter, and he writes two words?

Martha the snake had told me not to feel disappointed. Maybe Poseidon had a reason for being so vague. Maybe he didn’t know exactly what he was warning me about, but he sensed something big was about to happen—something that could completely knock me off my feet unless I was prepared. It was hard, but I tried to turn my thoughts to the race.

As Annabeth and I drove onto the track, I couldn’t help admiring the work Tyson had done on the Athena chariot. The carriage gleamed with bronze reinforcements. The wheels were realigned with magical suspension so we glided along with hardly a bump. The rigging for the horses was so perfectly balanced that the team turned at the slightest tug of the reins.

Tyson had also made us two javelins, each with three buttons on the shaft. The first button primed the javelin to explode on impact, releasing razor wire that would tangle and shred an opponent’s wheels. The second button produced a blunt (but still very painful) bronze spearhead designed to knock a driver out of his carriage. The third button brought up a grappling hook that could be used to lock onto an enemy’s chariot or push it away.

I figured we were in pretty good shape for the race, but Tyson still warned me to be careful.

The other chariot teams had plenty of tricks up their togas.

“Here,” he said, just before the race began.

He handed me a wristwatch. There wasn’t anything special about it—just a white-and-silver clock face, a black leather strap—but as soon as I saw it I realized that this is what I’d seen him tinkering on all summer.

I didn’t usually like to wear watches. Who cared what time it was? But I couldn’t say no to Tyson.

“Thanks, man.” I put it on and found it was surprisingly light and comfortable. I could hardly tell I was wearing it.

“Didn’t finish in time for the trip,” Tyson mumbled. “Sorry, sorry.”

“Hey, man. No big deal.”

“If you need protection in race,” he advised, “hit the button.”

“Ah, okay.” I didn’t see how keeping time was going to help a whole lot, but I was touched that Tyson was concerned. I promised him I’d remember the watch. “And, hey, um, Tyson …”

He looked at me.

“I wanted to say, well …” I tried to figure out how to apologize for getting embarrassed about him before the quest, for telling everyone he wasn’t my real brother. It wasn’t easy to find the words.

“I know what you will tell me,” Tyson said, looking ashamed. “Poseidon did care for me after all.”

“Uh, well—”

“He sent you to help me. Just what I asked for.”

I blinked. “You asked Poseidon for … me?”

“For a friend,” Tyson said, twisting his shirt in his hands. “Young Cyclopes grow up alone on the streets, learn to make things out of scraps. Learn to survive.”

“But that’s so cruel!”

He shook his head earnestly. “Makes us appreciate blessings, not be greedy and mean and fat like Polyphemus. But I got scared. Monsters chased me so much, clawed me sometimes—”

“The scars on your back?”

A tear welled in his eye. “Sphinx on Seventy-second Street. Big bully. I prayed to Daddy for help. Soon the people at Meriwether found me. Met you. Biggest blessing ever. Sorry I said Poseidon was mean. He sent me a brother.”

I stared at the watch that Tyson had made me.

“Percy!” Annabeth called. “Come on!”

Chiron was at the starting line, ready to blow the conch.

“Tyson …” I said.

“Go,” Tyson said. “You will win!”

“I—yeah, okay, big guy. We’ll win this one for you.” I climbed on board the chariot and got into position just as Chiron blew the starting signal.

The horses knew what to do. We shot down the track so fast I would’ve fallen out if my arms hadn’t been wrapped in the leather reins. Annabeth held on tight to the rail. The wheels glided beautifully. We took the first turn a full chariot-length ahead of Clarisse, who was busy trying to fight off a javelin attack from the Stoll brothers in the Hermes chariot.

“We’ve got ‘em!” I yelled, but I spoke too soon.

“Incoming!” Annabeth yelled. She threw her first javelin in grappling hook mode, knocking away a lead-weighted net that would have entangled us both. Apollo’s chariot had come up on our flank. Before Annabeth could rearm herself, the Apollo warrior threw a javelin into our right wheel.

The javelin shattered, but not before snapping some of our spokes. Our chariot lurched and wobbled. I was sure the wheel would collapse altogether, but we somehow kept going.

I urged the horses to keep up the speed. We were now neck and neck with Apollo.

Hephaestus was coming up close behind. Ares and Hermes were falling behind, riding side by side as Clarisse went sword-on-javelin with Connor Stoll.

If we took one more hit to our wheel, I knew we would capsize.

“You’re mine!” the driver from Apollo yelled. He was a first-year camper. I didn’t remember his name, but he sure was confident.

“Yeah, right!” Annabeth yelled back.

She picked up her second javelin—a real risk considering we still had one full lap to go—and threw it at the Apollo driver.

Her aim was perfect. The javelin grew a heavy spear point just as it caught the driver in the chest, knocking him against his teammate and sending them both toppling out of their chariot in a backward somersault. The horses felt the reins go slack and went crazy, riding straight for the crowd. Campers scrambled for cover as the horses leaped the corner of the bleachers and the golden chariot flipped over. The horses galloped back toward their stable, dragging the upside-down chariot behind them.

I held our own chariot together through the second turn, despite the groaning of the right wheel. We passed the starting line and thundered into our final lap.

The axle creaked and moaned. The wobbling wheel was making us lose speed, even though the horses were responding to my every command, running like a well-oiled machine.

The Hephaestus team was still gaining.

Beckendorf grinned as he pressed a button on his command console. Steel cables shot out of the front of his mechanical horses, wrapping around our back rail. Our chariot shuddered as Beckendorf’s winch system started working—pulling us backward while Beckendorf pulled himself forward.

Annabeth cursed and drew her knife. She hacked at the cables but they were too thick.

“Can’t cut them.’” she yelled.

The Hephaestus chariot was now dangerously close, their horses about to trample us underfoot.

“Switch with me!” I told Annabeth. “Take the reins!”

“But—”

“Trust me!”

She pulled herself to the front and grabbed the reins. I turned, trying hard to keep my footing, and uncapped Riptide.

I slashed down and the cables snapped like kite string. We lurched forward, but Beckendorf’s driver just swung his chariot to our left and pulled up next to us. Beckendorf drew his sword. He slashed at Annabeth, and I parried the blade away.

We were coming up on the last turn. We’d never make it. I needed to disable the Hephaestus chariot and get it out of the way, but I had to protect Annabeth, too. Just because Beckendorf was a nice guy didn’t mean he wouldn’t send us both to the infirmary if we let our guard down.

We were neck and neck now, Clarisse coming up from behind, making up for lost time.

“See ya, Percy!” Beckendorf yelled. “Here’s a little parting gift!”

He threw a leather pouch into our chariot. It stuck to the floor immediately and began billowing green smoke.

“Greek fire!” Annabeth yelled.

I cursed. I’d heard stories about what Greek fire could do. I figured we had maybe ten seconds before it exploded.

“Get rid of it!” Annabeth shouted, but I couldn’t. Hephaestus’s chariot was still alongside, waiting until the last second to make sure their little present blew up. Beckendorf was keeping me busy with his sword. If I let my guard down long enough to deal with the Greek fire, Annabeth would get sliced and we’d crash anyway. I tried to kick the leather pouch away with my foot, but I couldn’t.