Frank looked up. Shadows were shifting across the nearest mountain, forming the face of a sleeping woman.

You will never reach home in time, taunted the voice of Gaea. Even now, Thanatos is attending the death of Camp Jupiter, the final destruction of your Roman friends.

The mountain rumbled as if the whole earth were laughing. The shadows disappeared.

Hazel and Frank looked at each other. Neither said a word. They climbed onto Arion and sped back toward Glacier Bay.

XLVIII Frank

PERCY WAS WAITING FOR THEM. He looked mad.

He stood at the edge of the glacier, leaning on the staff with the golden eagle, gazing down at the wreckage he’d caused: several hundred acres of newly open water dotted with icebergs and flotsam from the ruined camp.

The only remains on the glacier were the main gates, which listed sideways, and a tattered blue banner lying over a pile of snow-bricks.

When they ran up to him, Percy said, “Hey,” like they were just meeting for lunch or something.

“You’re alive!” Frank marveled.

Percy frowned. “The fall? That was nothing. I fell twice that far from the St. Louis Arch.”

“You did what?” Hazel asked.

“Never mind. The important thing was I didn’t drown.”

“So the prophecy was incomplete!” Hazel grinned. “It probably said something like: The son of Neptune will drown a whole bunch of ghosts.”

Percy shrugged. He was still looking at Frank like he was miffed. “I got a bone to pick with you, Zhang. You can turn into an eagle? And a bear?”

“And an elephant,” Hazel said proudly.

“An elephant.” Percy shook his head in disbelief. “That’s your family gift? You can change shape?”

Frank shuffled his feet. “Um…yeah. Periclymenus, my ancestor, the Argonaut—he could do that. He passed down the ability.”

“And he got that gift from Poseidon,” Percy said. “That’s completely unfair. I can’t turn into animals.”

Frank stared at him. “Unfair? You can breathe underwater and blow up glaciers and summon freaking hurricanes—and it’s unfair that I can be an elephant?”

Percy considered. “Okay. I guess you got a point. But next time I say you’re totally beast—”

“Just shut up,” Frank said. “Please.”

Percy cracked a smile.

“If you guys are done,” Hazel said, “we need to go. Camp Jupiter is under attack. They could use that gold eagle.”

Percy nodded. “One thing first, though. Hazel, there’s about a ton of Imperial gold weapons and armor at the bottom of the bay now, plus a really nice chariot. I’m betting that stuff could come in handy.…”

It took them a long time—too long—but they all knew those weapons could make the difference between victory and defeat if they got them back to camp in time.

Hazel used her abilities to levitate some items from the bottom of the sea. Percy swam down and brought up more. Even Frank helped by turning into a seal, which was kind of cool, though Percy claimed his breath smelled like fish.

It took all three of them to raise the chariot, but finally they’d managed to haul everything ashore to a black sand beach near the base of the glacier. They couldn’t fit everything in the chariot, but they used Frank’s rope to strap down most of the gold weapons and the best pieces of armor.

“It looks like Santa’s sleigh,” Frank said. “Can Arion even pull that much?”

Arion huffed.

“Hazel,” Percy said, “I am seriously going to wash your horse’s mouth with soap. He says, yes, he can pull it, but he needs food.”

Hazel picked up an old Roman dagger, a pugio. It was bent and dull, so it wouldn’t be much good in a fight, but it looked like solid Imperial gold.

“Here you go, Arion,” she said. “High-performance fuel.”

The horse took the dagger in his teeth and chewed it like an apple. Frank made a silent oath never to put his hand near that horse’s mouth.

“I’m not doubting Arion’s strength,” he said carefully, “but will the chariot hold up? The last one—”

“This one has Imperial gold wheels and axle,” Percy said. “It should hold.”

“If not,” Hazel said, “this is going to be a short trip. But we’re out of time. Come on!”

Frank and Percy climbed into the chariot. Hazel swung up onto Arion’s back.

“Giddyup!” she yelled.

The horse’s sonic boom echoed across the bay. They sped south, avalanches tumbling down the mountains as they passed.

XLIX Percy

FOUR HOURS.

That’s how long it took the fastest horse on the planet to get from Alaska to San Francisco Bay, heading straight over the water down the Northwest Coast.

That’s also how long it took for Percy’s memory to return completely. The process had started in Portland when he had drunk the gorgon’s blood, but his past life had still been maddeningly fuzzy. Now, as they headed back into the Olympian gods’ territory, Percy remembered everything: the war with Kronos, his sixteenth birthday at Camp Half-Blood, his trainer Chiron the centaur, his best friend Grover, his brother Tyson, and most of all Annabeth—two great months of dating, and then BOOM. He’d been abducted by the alien known as Hera. Or Juno…whatever.

Eight months of his life stolen. Next time Percy saw the Queen of Olympus, he was definitely going to give her a goddess-sized slap upside the head.

His friends and family must be going out of their minds. If Camp Jupiter was in such bad trouble, he could only guess what Camp Half-Blood must be facing without him.

Even worse: Saving both camps would be only the beginning. According to Alcyoneus, the real war would happen far away, in the homeland of the gods. The giants intended to attack the original Mount Olympus and destroy the gods forever.

Percy knew that giants couldn’t die unless demigods and gods fought them together. Nico had told him that. Annabeth had mentioned it too, back in August, when she’d speculated that the giants might be part of the new Great Prophecy—what the Romans called the Prophecy of Seven. (That was the downside of dating the smartest girl at camp: You learn stuff.)

He understood Juno’s plan: Unite the Roman and Greek demigods to create an elite team of heroes, then somehow convince the gods to fight alongside them. But first, they had to save Camp Jupiter.

The coastline began to look familiar. They raced past the Mendocino lighthouse. Shortly afterward, Mount Tam and the Marin headlands loomed out of the fog. Arion shot straight under the Golden Gate Bridge into San Francisco Bay.

They tore through Berkeley and into the Oakland Hills. When they reached the hilltop above the Caldecott Tunnel, Arion shuddered like a broken car and came to a stop, his chest heaving.

Hazel patted his sides lovingly. “You did great, Arion.”

The horse was too tired even to cuss: Of course I did great. What did you expect?

Percy and Frank jumped off the chariot. Percy wished there’d been comfortable seats or an in-flight meal. His legs were wobbly. His joints were so stiff, he could barely walk. If he went into battle like this, the enemy would call him Old Man Jackson.

Frank didn’t look much better. He hobbled to the top of the hill and peered down at the camp. “Guys…you need to see this.”

When Percy and Hazel joined him, Percy’s heart sank. The battle had begun, and it wasn’t going well. The Twelfth Legion was arrayed on the Field of Mars, trying to protect the city. Scorpions fired into the ranks of the Earthborn. Hannibal the elephant plowed down monsters right and left, but the defenders were badly outnumbered.

On her pegasus Scipio, Reyna flew around the giant Polybotes, trying to keep him occupied. The Lares had formed shimmering purple lines against a mob of black, vaporous shades in ancient armor. Veteran demigods from the city had joined the battle, and were pushing their shield wall against an onslaught of wild centaurs. Giant eagles circled the battlefield, doing aerial combat with two snake-haired ladies in green Bargain Mart vests—Stheno and Euryale.

The legion itself was taking the brunt of the attack, but their formation was breaking. Each cohort was an island in a sea of enemies. The Cyclopes’ siege tower shot glowing green cannonballs into the city, blasting craters in the forum, reducing houses to ruins. As Percy watched, a cannonball hit the Senate House and the dome partially collapsed.

“We’re too late,” Hazel said.

“No,” Percy said. “They’re still fighting. We can do this.”

“Where’s Lupa?” Frank asked, desperation creeping into his voice. “She and the wolves…they should be here.”

Percy thought about his time with the wolf goddess. He’d come to respect her teachings, but he’d also learned that wolves had limits. They weren’t front-line fighters. They only attacked when they had vastly superior numbers, and usually under the cover of darkness. Besides, Lupa’s first rule was self-sufficiency. She would help her children as much as she could, train them to fight—but in the end, they were either predator or prey. Romans had to fight for themselves. They had to prove their worth or die. That was Lupa’s way.

“She did what she could,” Percy said. “She slowed down the army on its way south. Now it’s up to us. We’ve got to get the gold eagle and these weapons to the legion.”

“But Arion is out of steam!” Hazel said. “We can’t haul this stuff ourselves.”

“Maybe we don’t have to.” Percy scanned the hilltops. If Tyson had gotten his dream message in Vancouver, help might be close.

He whistled as loud as he could—a good New York cab whistle that would’ve been heard all the way from Times Square to Central Park.

Shadows rippled in the trees. A huge black shape bounded out of nowhere—a mastiff the size of an SUV, with a Cyclops and a harpy on her back.

“Hellhound!” Frank scrambled backward.

“It’s okay!” Percy grinned. “These are friends.”

“Brother!” Tyson climbed off and ran toward Percy. Percy tried to brace himself, but it was no good. Tyson slammed into him and smothered him in a hug. For a few seconds, Percy could only see black spots and lots of flannel. Then Tyson let go and laughed with delight, looking Percy over with that massive baby brown eye.

“You are not dead!” he said. “I like it when you are not dead!”

Ella fluttered to the ground and began preening her feathers. “Ella found a dog,” she announced. “A large dog. And a Cyclops.”

Was she blushing? Before Percy could decide, his black mastiff pounced on him, knocking Percy to the ground and barking so loudly that even Arion backed up.

“Hey, Mrs. O’Leary,” Percy said. “Yeah, I love you too, girl. Good dog.”

Hazel made a squeaking sound. “You have a hellhound named Mrs. O’Leary?”“Long story.” Percy managed to get to his feet and wipe off the dog slobber. “You can ask your brother…”

His voice wavered when he saw Hazel’s expression. He’d almost forgotten that Nico di Angelo was missing.