The High Line was empty, though—maybe because it was a workday, or maybe because the visitors were smart and ran when they heard the explosions.

Somewhere below us, Cacus was roaring, cursing, and offering panicked mortals deep discounts on slightly damp Rolexes. I figured we only had a few seconds before he found us.

I scanned the park, hoping for something that would help. All I saw were benches, walkways, and lots of plants. I wished we had a child of Demeter with us. Maybe they could entangle the giant in vines, or turn flowers into ninja throwing stars. I’d never actually seen a child of Demeter do that, but it would be cool.

I looked at Annabeth. “Your turn for a brilliant idea.”

“I’m working on it.” She was beautiful in combat. I know that’s a crazy thing to say, especially after we’d just climbed a sewage waterfall, but her gray eyes sparkled when she was fighting for her life. Her face shone like a goddess’s, and believe me, I’ve seen goddesses. The way her Camp Half-Blood beads rested against her throat—Okay, sorry. Got a little distracted.

She pointed. “There!”

A hundred feet away, the old railroad tracks split and the elevated platform formed a Y. The shorter piece of the Y was a dead end—part of the park that was still under construction. Stacks of potting soil bags and plant flats sat on the gravel. Jutting over the edge of the railing was the arm of a crane that must’ve been sitting down at ground level. Far above us, a big metal claw hung from the crane’s arm—probably what they’d been using to hoist garden supplies.

Suddenly I understood what Annabeth was planning, and I felt like I was trying to swallow a quarter. “No,” I said. “Too dangerous.”

Annabeth raised her eyebrow. “Percy, you know I rock at grabber-arm games.”

That was true. I’d taken her to the arcade at Coney Island, and we’d come back with a sackful of stuffed animals. But this crane was massive.

“Don’t worry,” she promised. “I’ve supervised bigger equipment on Mount Olympus.”

My girlfriend: sophomore honors student, demigod, and—oh, yeah—head architect for redesigning the palace of the gods on Mount Olympus in her spare time.

“But can you operate it?” I asked.

“Cakewalk. Just lure him over there. Keep him occupied while I grab him.”

“And then what?”

She smiled in a way that made me glad I wasn’t the giant.

“You’ll see. If you can snag the caduceus while he’s distracted, that would be great.”

“Anything else?” I asked. “Would you like fries and a drink, maybe?”

“Shut up, Percy.”

“DEATH!” Cacus stormed up the steps and onto the High Line. He spotted us and lumbered over with slow, grim determination.

Annabeth ran. She reached the crane and leaped over the side of the railing, shinnying down the metal arm like it was a tree branch. She disappeared from view.

I raised my sword and faced the giant. His red velour robe was in tatters. He’d lost his slippers. His ginger hair was plastered to his head like a greasy shower cap. He aimed his glowing bazooka.

“George, Martha,” I called, hoping they could hear me. “Please change out of laser mode.”

We’re trying, dear! Martha said.

My stomach hurts, George said. I think he bruised my tummy.

I backed up slowly down the dead end tracks, edging toward the crane. Cacus followed. Now that he had me trapped, he seemed in no hurry to kill me. He stopped twenty feet away, just beyond the shadow of the crane’s hook. I tried to look cornered and panicked. It wasn’t hard.

“So,” Cacus growled. “Any last words?”

“Help,” I said. “Yikes. Ouch. How are those? Oh, and Hermes is a way better salesman than you.”

“Gah!” Cacus lowered the caduceus laser.

The crane didn’t move. Even if Annabeth could get it started, I wondered how she could see her target from down below. I probably should’ve thought of that sooner.

Cacus pulled the trigger, and suddenly the caduceus changed form. The giant tried to zap me with a credit card–swiping machine, but the only thing that came out was a paper receipt.

Oh, yeah! George yelled in my mind. One for the snakes!

“Stupid staff!” Cacus threw down the caduceus in disgust, which was the chance I’d been waiting for. I launched myself forward, snatched the staff, and rolled under the giant’s legs.

When I got to my feet, we’d changed positions. Cacus had his back to the crane. Its arm was right behind him, the claw perfectly positioned above his head.

Unfortunately, the crane still wasn’t moving. And Cacus still wanted to kill me.

“You put out my fire with that cursed sewage,” he growled. “Now you steal my staff.”

“Which you wrongfully stole,” I said.

“It doesn’t matter.” Cacus cracked his knuckles. “You can’t use the staff either. I’ll simply kill you with my bare hands.”

The crane shifted, slowly and almost silently. I realized there were mirrors fixed along the side of the arm—like rearview mirrors to guide the operator. And reflected in one of those mirrors were Annabeth’s gray eyes.

The claw opened and began to drop.

I smiled at the giant. “Actually, Cacus, I have another secret weapon.”

The giant’s eyes lit up with greed. “Another weapon? I will steal it! I will copy it and sell the knockoffs for a profit! What is this secret weapon?”

“Her name is Annabeth,” I said. “And she’s one of a kind.”

The claw dropped, smacking Cacus on the head and knocking him to the ground. While the giant was dazed, the claw closed around his chest and lifted him into the air.

“Wh—what is this?” The giant came to his senses twenty feet up. “Put me down!”

He squirmed uselessly and tried to blow fire, but only managed to cough up some mud.

Annabeth swung the crane arm back and forth, building momentum as the giant cursed and struggled. I was afraid the whole crane would tip over, but Annabeth’s control was perfect. She swung the arm one last time and opened the claw when the giant was at the top of his arc.

“Aahhhhhhhhh!” The giant sailed over the rooftops, straight over Chelsea Piers, and began falling toward the Hudson River.

“George, Martha,” I said. “Do you think you could manage laser mode just once more for me?”

With pleasure, George said.

The caduceus turned into a wicked high-tech bazooka.

I took aim at the falling giant and yelled, “Pull!”

The caduceus blasted its beam of blue light, and the giant disintegrated into a beautiful starburst.

That, George said, was excellent. May I have a rat now?

I have to agree with George, Martha said. A rat would be lovely.

“You’ve earned it,” I said. “But first we’d better check on Annabeth.”

She met me at the steps of the park, grinning like crazy.

“Was that amazing?” she demanded.

“That was amazing,” I agreed. It’s hard to pull off a romantic kiss when you’re both drenched in muck, but we gave it our best shot.

When I finally came up for air, I said, “Rats.”

“Rats?” she asked.

“For the snakes,” I said. “And then—”

“Oh, gods.” She pulled out her phone and checked the time. “It’s almost five. We have to get the caduceus back to Hermes!”

The surface streets were clogged with emergency vehicles and minor accidents, so we took the subway back. Besides, the subway had rats. Without going into gruesome details, I can tell you that George and Martha helped out with the vermin problem. As we traveled north, they curled around the caduceus and dozed contentedly with bulging bellies.

We met Hermes by the Atlas statue at Rockefeller Center. (The statue, by the way, looks nothing like the real Atlas, but that’s another story.)

“Thank the Fates!” Hermes cried. “I’d just about given up hope!”

He took the caduceus and patted the heads of his sleepy snakes. “There, there, my friends. You’re home now.”

Zzzzz, said Martha.

Yummy, George murmured in his sleep.

Hermes sighed with relief. “Thank you, Percy.”

Annabeth cleared her throat.

“Oh, yes,” the god added, “and you, too, girl. I just have time to finish my deliveries! But what happened with Cacus?”

We told him the story. When I related what Cacus had said about someone else giving him the idea to steal the caduceus, and about the gods having other enemies, Hermes’s face darkened.

“Cacus wanted to cut the gods’ communication lines, did he?” Hermes mused. “That’s ironic, considering Zeus has been threatening…”

His voice trailed off.

“What?” Annabeth asked. “Zeus has been threatening what?”

“Nothing,” Hermes said.

It was obviously a lie, but I’d learned that it’s best not to confront gods when they lie to your face. They tend to turn you into small fuzzy mammals or potted plants.

“Okay…” I said. “Any idea what Cacus meant about other enemies, or who would want him to steal your caduceus?”

Hermes fidgeted. “Oh, could be any number of enemies. We gods do have many.”

“Hard to believe,” Annabeth said.

Hermes nodded. Apparently he didn’t catch the sarcasm, or he had other things on his mind. I got the feeling the giant’s warnings would come back to haunt us sooner or later, but Hermes obviously wasn’t going to enlighten us now.

The god managed a smile. “At any rate, well done, both of you! Now I must be going. So many stops—”

“There’s the small matter of my reward,” I reminded him.

Annabeth frowned. “What reward?”

“It’s our one-month anniversary,” I said. “Surely you didn’t forget.”

She opened her mouth and closed it again. I don’t leave her speechless very often. I have to enjoy those rare moments.

“Ah, yes, your reward.” Hermes looked us up and down. “I think we’ll have to start with new clothes. Manhattan sewage is not a look you can pull off. Then the rest should be easy. God of travel, at your service.”

“What is he talking about?” Annabeth asked.

“A special surprise for dinner,” I said. “I did promise.”

Hermes rubbed his hands. “Say good-bye, George and Martha.”

Good-bye, George and Martha, said George sleepily.

Zzz, said Martha.

“I may not see you for a while, Percy,” Hermes warned. “But…well, enjoy tonight.”

He made that sound so ominous, I wondered again what he wasn’t telling me. Then he snapped his fingers, and the world dissolved around us.

Our table was ready. The ma?tre d’ seated us on a rooftop terrace with a view of the lights of Paris and the boats on the River Seine. The Eiffel Tower glowed in the distance.

I was wearing a suit. I hope someone got a picture, because I don’t wear suits. Thankfully, Hermes had magically arranged this. Otherwise I couldn’t have tied the tie. Hopefully I looked okay, because Annabeth looked stunning. She wore a dark green sleeveless dress that showed off her long blond hair and her slim athletic figure. Her camp necklace had been replaced by a string of gray pearls that matched her eyes.