Annabeth had said ... well, he tried not to think about Annabeth. He still felt guilty about her and Percy falling into Tartarus. Leo knew it was his fault. He should have got everyone safely on board the Argo II before he started securing the statue. He should have realized the cavern floor was unstable.

Still, moping around wasn't going to get Percy and Annabeth back. He had to concentrate on fixing the problems he could fix.

Anyway, Annabeth had said the statue was the key to defeating Gaia. It could heal the rift between Greek and Roman demiG.o.ds. Leo figured there had to be more to it than just symbolism. Maybe Athena's eyes shot lasers, or the snake behind her shield could spit poison. Or maybe the smaller figure of Nike came to life and busted out some ninja moves.

Leo could think of all kinds of fun things the statue might do if he had designed it, but the more he examined it, the more frustrated he got. The Athena Parthenos radiated magic. Even he could feel that. But it didn't seem to do anything except look impressive.

The ship careened to one side, taking evasive manoeuvres. Leo resisted the urge to run to the helm. Jason, Piper and Frank were on duty with Hazel now. They could handle whatever was going on. Besides, Hazel had insisted on taking the wheel to guide them through the secret pa.s.s that the magic G.o.ddess had told her about.

Leo hoped Hazel was right about the long detour north. He didn't trust this Hecate lady. He didn't see why such a creepy G.o.ddess would suddenly decide to be helpful.

Of course, he didn't trust magic in general. That's why he was having so much trouble with the Athena Parthenos. It had no moving parts. Whatever it did, it apparently operated on pure sorcery ... and Leo didn't appreciate that. He wanted it to make sense, like a machine.

Finally he got too exhausted to think straight. He curled up with a blanket in the engine room and listened to the soothing hum of the generators. Buford the mechanical table sat in the corner in sleep mode, making little steamy snores: Shhh, pfft, shh, pfft.

Leo liked his quarters okay, but he felt safest here in the heart of the ship in a room filled with mechanisms he knew how to control. Besides, maybe if he spent more time close to the Athena Parthenos, he would eventually soak in its secrets.

'It's you or me, Big Lady,' he murmured as he pulled the blanket up to his chin. 'You're gonna cooperate eventually.'

He closed his eyes and slept. Unfortunately, that meant dreams.

He was running for his life through his mother's old workshop, where she'd died in a fire when Leo was eight.

He wasn't sure what was chasing him, but he sensed it closing fast something large and dark and full of hate.

He stumbled into workbenches, knocked over toolboxes and tripped on electrical cords. He spotted the exit and sprinted towards it, but a figure loomed in front of him a woman in robes of dry swirling earth, her face covered in a veil of dust.

Where are you going, little hero? Gaia asked. Stay and meet my favourite son.

Leo darted to the left, but the Earth G.o.ddess's laughter followed him.

The night your mother died, I warned you. I said the Fates would not allow me to kill you then. But now you have chosen your path. Your death is near, Leo Valdez.

He ran into a drafting table his mother's old workstation. The wall behind it was decorated with Leo's crayon drawings. He sobbed in desperation and turned, but the thing pursuing him now stood in his path a colossal being wrapped in shadows, its shape vaguely humanoid, its head almost sc.r.a.ping the ceiling twenty feet above.

Leo's hands burst into flame. He blasted the giant, but the darkness consumed his fire. Leo reached for his tool belt. The pockets were sewn shut. He tried to speak to say anything that would save his life but he couldn't make a sound, as if the air had been stolen from his lungs.

My son will not allow any fires tonight, Gaia said from the depths of the warehouse. He is the void that consumes all magic, the cold that consumes all fire, the silence that consumes all speech.

Leo wanted to shout: And I'm the dude that's all out of here!

His voice didn't work, so he used his feet. He dashed to the right, ducking under the shadowy giant's grasping hands, and burst through the nearest doorway.

Suddenly, he found himself at Camp Half-Blood, except the camp was in ruins. The cabins were charred husks. Burnt fields smouldered in the moonlight. The dining pavilion had collapsed into a pile of white rubble, and the Big House was on fire, its windows glowing like demon eyes.

Leo kept running, sure the shadow giant was still behind him.

He weaved around the bodies of Greek and Roman demiG.o.ds. He wanted to check if they were alive. He wanted to help them. But somehow he knew he was running out of time.

He jogged towards the only living people he saw a group of Romans standing at the volleyball pit. Two centurions leaned casually on their javelins, chatting with a tall skinny blond guy in a purple toga. Leo stumbled. It was that freak Octavian, the augur from Camp Jupiter, who was always screaming for war.

Octavian turned to face him, but he seemed to be in a trance. His features were slack, his eyes closed. When he spoke, it was in Gaia's voice: This cannot be prevented. The Romans move east from New York. They advance on your camp, and nothing can slow them down.

Leo was tempted to punch Octavian in the face. Instead he kept running.

He climbed Half-Blood Hill. At the summit, lightning had splintered the giant pine tree.

He faltered to a stop. The back of the hill was shorn away. Beyond it, the entire world was gone. Leo saw nothing but clouds far below a rolling silver carpet under the dark sky.

A sharp voice said, 'Well?'

Leo flinched.

At the shattered pine tree, a woman knelt at a cave entrance that had cracked open between the tree's roots.

The woman wasn't Gaia. She looked more like a living Athena Parthenos, with the same golden robes and bare ivory arms. When she rose, Leo almost stumbled off the edge of the world.

Her face was regally beautiful, with high cheekbones, large dark eyes and braided liquorice-coloured hair piled in a fancy Greek hairdo, set with a spiral of emeralds and diamonds so that it reminded Leo of a Christmas tree. Her expression radiated pure hatred. Her lip curled. Her nose wrinkled.

'The tinkerer G.o.d's child,' she sneered. 'You are no threat, but I suppose my vengeance must start somewhere. Make your choice.'

Leo tried to speak, but he was about to crawl out of his skin with panic. Between this hate queen and the giant chasing him, he had no idea what to do.

'He'll be here soon,' the woman warned. 'My dark friend will not give you the luxury of a choice. It's the cliff or the cave, boy!'

Suddenly Leo understood what she meant. He was cornered. He could jump off the cliff, but that was suicide. Even if there was land under those clouds, he would die in the fall, or maybe he would just keep falling forever.

But the cave ... He stared at the dark opening between the tree roots. It smelled of rot and death. He heard bodies shuffling inside, voices whispering in the shadows.

The cave was the home of the dead. If he went down there, he would never come back.

'Yes,' the woman said. Around her neck hung a strange bronze-and-emerald pendant, like a circular labyrinth. Her eyes were so angry, Leo finally understood why mad was a word for crazy. This lady had been driven nuts by hatred. 'The House of Hades awaits. You will be the first puny rodent to die in my maze. You have only one chance to escape, Leo Valdez. Take it.'

She gestured towards the cliff.

'You're bonkers,' he managed.

That was the wrong thing to say. She seized his wrist. 'Perhaps I should kill you now, before my dark friend arrives?'

Steps shook the hillside. The giant was coming, wrapped in shadows, huge and heavy and bent on murder.

'Have you heard of dying in a dream, boy?' the woman asked. 'It is possible, at the hands of a sorceress!'

Leo's arm started to smoke. The woman's touch was acid. He tried to free himself, but her grip was like steel.

He opened his mouth to scream. The ma.s.sive shape of the giant loomed over him, obscured by layers of black smoke.

The giant raised his fist, and a voice cut through the dream.

'Leo!' Jason was shaking his shoulder. 'Hey, man, why are you hugging Nike?'

Leo's eyes fluttered open. His arms were wrapped around the human-sized statue in Athena's hand. He must have been thrashing in his sleep. He clung to the victory G.o.ddess like he used to cling to his pillow when he had nightmares as a kid. (Man, that had been so embarra.s.sing in the foster homes.) He disentangled himself and sat up, rubbing his face.

'Nothing,' he muttered. 'We were just cuddling. Um, what's going on?'

Jason didn't tease him. That's one thing Leo appreciated about his friend. Jason's ice-blue eyes were level and serious. The little scar on his mouth twitched like it always did when he had bad news to share.

'We made it through the mountains,' he said. 'We're almost to Bologna. You should join us in the mess hall. Nico has new information.'

LEO.

LEO HAD DESIGNED the mess hall's walls to show real-time scenes from Camp Half-Blood. At first he had thought that was a pretty awesome idea. Now he wasn't so sure.

The scenes from back home the campfire sing-alongs, dinners at the pavilion, volleyball games outside the Big House just seemed to make his friends sad. The further they got from Long Island, the worse it got. The time zones kept changing, making Leo feel the distance every time he looked at the walls. Here in Italy the sun had just come up. Back at Camp Half-Blood it was the middle of the night. Torches sputtered at the cabin doorways. Moonlight glittered on the waves of Long Island Sound. The beach was covered in footprints, as if a big crowd had just left.

With a start, Leo realized that yesterday last night, whatever had been the Fourth of July. They'd missed Camp Half-Blood's annual party at the beach with awesome fireworks prepared by Leo's siblings in Cabin Nine.

He decided not to mention that to the crew, but he hoped their buddies back home had had a good celebration. They needed something to keep their spirits up, too.

He remembered the images he'd seen in his dream the camp in ruins, littered with bodies; Octavian standing at the volleyball pit, casually talking in Gaia's voice.

He stared down at his eggs and bacon. He wished he could turn off the wall videos.

'So,' Jason said, 'now that we're here ...'

He sat at the head of the table, kind of by default. Since they'd lost Annabeth, Jason had done his best to act as the group's leader. Having been praetor back at Camp Jupiter, he was probably used to that, but Leo could tell his friend was stressed. His eyes were more sunken than usual. His blond hair was uncharacteristically messy, like he'd forgotten to comb it.

Leo glanced at the others around the table. Hazel was bleary-eyed, too, but of course she'd been up all night guiding the ship through the mountains. Her curly cinnamon-coloured hair was tied back in a bandanna, which gave her a commando look that Leo found kind of hot and then immediately felt guilty about.

Next to her sat her boyfriend Frank Zhang, dressed in black workout pants and a Roman tourist T-shirt that said CIAO! (was that even a word?). Frank's old centurion badge was pinned to his shirt, despite the fact that the demiG.o.ds of the Argo II were now Public Enemies Numbers 1 through 7 back at Camp Jupiter. His grim expression just reinforced his unfortunate resemblance to a sumo wrestler. Then there was Hazel's half-brother, Nico di Angelo. Dang, that kid gave Leo the freaky-deakies. He sat back in his leather aviator jacket, his black T-shirt and jeans, that wicked silver skull ring on his finger and the Stygian sword at his side. His tufts of black hair stuck up in curls like baby bat wings. His eyes were sad and kind of empty, as if he'd stared into the depths of Tartarus which he had.

The only absent demiG.o.d was Piper, who was taking her turn at the helm with Coach Hedge, their satyr chaperone.

Leo wished Piper were here. She had a way of calming things down with that Aphrodite charm of hers. After his dreams last night, Leo could use some calm.

On the other hand, it was probably good she was above deck chaperoning their chaperone. Now that they were in the ancient lands, they had to be constantly on guard. Leo was nervous about letting Coach Hedge fly solo. The satyr was a little trigger-happy, and the helm had plenty of bright, dangerous b.u.t.tons that could cause the picturesque Italian villages below them to go BOOM!

Leo had zoned out so totally he didn't realize Jason was still talking.

' the House of Hades,' he was saying. 'Nico?'

Nico sat forward. 'I communed with the dead last night.'

He just tossed that line out there, like he was saying he got a text from a buddy.

'I was able to learn more about what we'll face,' Nico continued. 'In ancient times, the House of Hades was a major site for Greek pilgrims. They would come to speak with the dead and honour their ancestors.'

Leo frowned. 'Sounds like Dia de los Muertos. My Aunt Rosa took that stuff seriously.'

He remembered being dragged by her to the local cemetery in Houston, where they'd clean up their relatives' gravesites and put out offerings of lemonade, cookies and fresh marigolds. Aunt Rosa would force Leo to stay for a picnic, as if hanging out with dead people were good for his appet.i.te.

Frank grunted. 'Chinese have that, too ancestor worship, sweeping the graves in the springtime.' He glanced at Leo. 'Your Aunt Rosa would've got along with my grandmother.'

Leo had a terrifying image of his Aunt Rosa and some old Chinese woman in wrestlers' outfits, whaling on each other with spiked clubs.

'Yeah,' Leo said. 'I'm sure they would've been best buds.'

Nico cleared his throat. 'A lot of cultures have seasonal traditions to honour the dead, but the House of Hades was open year round. Pilgrims could actually speak to the ghosts. In Greek, the place was called the Necromanteion, the Oracle of Death. You'd work your way through different levels of tunnels, leaving offerings and drinking special potions '

'Special potions,' Leo muttered. 'Yum.'

Jason flashed him a look like, Dude, enough. 'Nico, go on.'

'The pilgrims believed that each level of the temple brought you closer to the Underworld, until the dead would appear before you. If they were pleased with your offerings, they would answer your questions, maybe even tell you the future.'

Frank tapped his mug of hot chocolate. 'And if the spirits weren't pleased?'

'Some pilgrims found nothing,' Nico said. 'Some went insane or died after leaving the temple. Others lost their way in the tunnels and were never seen again.'

'The point is,' Jason said quickly, 'Nico found some information that might help us.'

'Yeah.' Nico didn't sound very enthusiastic. 'The ghost I spoke to last night ... he was a former priest of Hecate. He confirmed what the G.o.ddess told Hazel yesterday at the crossroads. In the first war with the giants, Hecate fought for the G.o.ds. She slew one of the giants one who'd been designed as the anti-Hecate. A guy named Clytius.'

'Dark dude,' Leo guessed. 'Wrapped in shadows.'

Hazel turned towards him, her gold eyes narrowing. 'Leo, how did you know that?'

'Kind of had a dream.'

No one looked surprised. Most demiG.o.ds had vivid nightmares about what was going on in the world.

His friends paid close attention as Leo explained. He tried not to look at the wall images of Camp Half-Blood as he described the place in ruins. He told them about the dark giant and the strange woman on Half-Blood Hill, offering him a multiple-choice death.

Jason pushed away his plate of pancakes. 'So the giant is Clytius. I suppose he'll be waiting for us, guarding the Doors of Death.'

Frank rolled up one of the pancakes and started munching not a guy to let impending death stand in the way of a hearty breakfast. 'And the woman in Leo's dream?'

'She's my problem.' Hazel pa.s.sed a diamond between her fingers in a sleight of hand. 'Hecate mentioned a formidable enemy in the House of Hades a witch who couldn't be defeated except by me, using magic.'

'Do you know magic?' Leo asked.

'Not yet.'