PERCY WAS DEFENSELESS. His sword was gone and Kronos was about to strike.

They had made it to Olympus to warn the gods and make things right. They had lost some along the way, but had gained soldiers too. But Kronos had followed them.

"STOP!" Annabeth came from nowhere.

Kronos whirled to face her and slashed with Backbiter, but somehow Annabeth caught the strike on her dagger hilt. It was a move only the quickest and most skilled knife fighter could've managed. Don't ask him where she found the strength, but she stepped in closer for leverage, their blades crossed, and for a moment she stood face-to-face with the Titan lord, holding him at a standstill.

"Luke," she said, gritting her teeth, "I understand now. You have to trust me."

Kronos roared in outrage. "Luke Castellan is dead! His body will burn away as I assume my true form!"

Percy tried to move, but his body was frozen again. How could Annabeth, battered and half-dead with exhaustion, have the strength to fight a Titan like Kronos?

Kronos pushed against her, trying to dislodge his blade, but she held him in check, her arms trembling as he forced his sword down toward her neck.

"Your mother," Annabeth grunted. "She saw your fate."

"Service to Kronos!" the Titan roared. "This is my fate."

"No!" Annabeth insisted. Her eyes were tearing up, but Percy didn't know if it was from sadness or pain. "That's not the end, Luke. The prophecy, she saw what you would do. It applies to you!"

"I will crush you, child!" Kronos bellowed.

"You won't," Annabeth said. "You promised. You're holding Kronos back even now."

"LIES!" Kronos pushed again, and this time Annabeth lost her balance. With his free hand, Kronos struck her face, and she slid backward.

Percy summoned all his will. He managed to rise, but it was difficult. As if he was holding the sky like Selena had done once before.

Selena. Where was she?

Annabeth said she and Kasey had disappeared from the battle near the reservior. Percy could only pray to the gods that she was okay.

Kronos loomed over Annabeth, his sword raised.

Blood trickled from the corner of her mouth. She croaked, " You promised, Luke."

Percy took a painful step forward. Grover was back on his feet, over by the throne of Hera, but he seemed to be struggling to move as well. Before either of them could get anywhere close to Annabeth, Kronos staggered.

He stared at the knife in Annabeth's hand, the blood on her face. "Promise."

Then he gasped like he couldn't get air. "Annabeth . . ." But it wasn't the Titan's voice. It was Luke's. He stumbled forward like he couldn't control his own body. "You're bleeding. . . ."

"My knife." Annabeth tried to raise her dagger, but it clattered out of her hand. Her arm was bent at a funny angle. She looked at Percy, imploring, "Percy, please . . ."

He could move again.

Percy surged forward and scooped up her knife. He knocked Backbiter out of Luke's hand, and it spun into the hearth. Luke hardly paid Percy any attention. He stepped toward Annabeth, but Percy put himself between him and her.

"Don't touch her," He growled.

Anger rippled across his face. Kronos's voice growled: "Jackson..." Was it his imagination, or was his whole body glowing, turning gold?

He gasped again. Luke's voice: "He's changing. Help. He's... he's almost ready. He won't need my body anymore. Please—"

"NO!" Kronos bellowed. He looked around for his sword, but it was in the hearth, glowing among the coals.

He stumbled toward it. Percy tried to stop him, but he pushed him out of the way with such force Percy landed next to Annabeth and cracked his head on the base of Athena's throne.

"The knife, Percy," Annabeth muttered. Her breath was shallow. "Hero... cursed blade..."

When Percy's vision came back into focus, he saw Kronos grasping his sword. Then he bellowed in pain and dropped it. His hands were smoking and seared. The hearth fire had grown red-hot, like the scythe wasn't compatible with it. Percy saw an image of Hestia flickering in the ashes, frowning at Kronos with disapproval.

Luke turned and collapsed, clutching his ruined hands. "Please, Percy..."

Percy struggled to his feet. He moved toward Luke with the knife. He should kill him. That was the plan.

Luke seemed to know what Percy was thinking. He moistened his lips. "You can't... can't do it yourself. He'll break my control. He'll defend himself. Only my hand. I know where. I can... can keep him controlled."

He was definitely glowing now, his skin starting to smoke.

Percy raised the knife to strike. Then he looked at Annabeth, at Grover cradling her in his arms, trying to shield her. And Percy finally understood what she'd been trying to tell him.

You are not the hero, Rachel had said. It will affect what you do.

"Please," Luke groaned. "No time."

If Kronos evolved into his true form, there would be no stopping him. He would make Typhon look like a playground bully.

The line from the great prophecy echoed in my head: A hero's soul, cursed blade shall reap. Percy's whole world tipped upside down, and he gave the knife to Luke.

Grover yelped. "Percy? Are you... um..."

Crazy. Insane. Off his rocker. Probably.

But Percy watched as Luke grasped the hilt.

Percy stood before him—defenseless.

He unlatched the side straps of his armor, exposing a small bit of his skin just under his left arm, a place that would be very hard to hit. With difficulty, he stabbed himself.

It wasn't a deep cut, but Luke howled. His eyes glowed like lava. The throne room shook, throwing Percy off his feet. An aura of energy surrounded Luke, growing brighter and brighter. Percy shut his eyes and felt a force like a nuclear explosion blister his skin and crack his lips.

It was silent for a long time.

When Percy opened his eyes, he saw Luke sprawled at the hearth. On the floor around him was a blackened circle of ash. Kronos's scythe had liquefied into molten metal and was trickling into the coals of the hearth, which now glowed like a blacksmith's furnace.

Luke's left side was bloody. His eyes were open—blue eyes, the way they used to be. His breath was a deep rattle.

"Good . . . blade," he croaked.

Percy knelt next to him. Annabeth limped over with Grover's support. They both had tears in their eyes.

Luke gazed at Annabeth. "You knew. I almost killed you, but you knew..."

"Shhh." Her voice trembled. "You were a hero at the end, Luke. You'll go to Elysium."

He shook his head weakly. "Think... rebirth. Try for three times. Isles of the Blest."

Annabeth sniffled. "You always pushed yourself too hard."

He held up his charred hand. Annabeth touched his fingertips.

"Did you..." Luke coughed and his lips glistened red. "Did you love me?"

Annabeth wiped her tears away. "There was a time I thought... well, I thought..." Annabeth sighed, "You were like a brother to me, Luke," she said softly. "But I didn't love you."

He nodded, as if he'd expected it. He winced in pain.

"We can get ambrosia," Grover said. "We can—"

"Grover," Luke gulped. "You're the bravest satyr I ever knew. But no. There's no healing..." Another cough.

He gripped Percy's sleeve, and he could feel the heat of Luke's skin like a fire. "Ethan. Me. All the unclaimed. Don't let it... Don't let it happen again."

His eyes were angry, but pleading too.

"I won't," Percy said. "I promise."

Luke nodded, "I'm so sorry." He looked back over at Annabeth, "Maybe I'll get to see Selena one last time."

Annabeth stroked his hair, "I'm sure she'll be here soon. Just hold on."

Luke shook his head slowly, "I'll have my chance to apologise." Luke whispered and his hand went slack.

The gods arrived a few minutes later in their full war regalia, thundering into the throne room and expecting a battle.

What they found were Annabeth, Grover, and Percy standing over the body of a broken half-blood, in the dim warm light of the hearth.

"Percy," Poseidon called, awe in his voice. "What... what is this?"

He turned and faced the Olympians, "We need a shroud," Percy announced, his voice cracking. "A shroud for the son of Hermes."