‘Rachel,’ I said, ‘I wish I knew. Maybe we should ask Chiron –’

  She flinched like she’d got an electric shock. ‘Percy, something is about to happen. A trick that ends in death.’

  ‘What do you mean? Whose death?’

  ‘I don’t know.’ She looked around nervously. ‘Don’t you feel it?’

  ‘Is that the message you wanted to tell me?’

  ‘No.’ She hesitated. ‘I’m sorry. I’m not making sense, but that thought just came to me. The message I wrote on the beach was different. It had your name in it.’

  ‘Perseus,’ I remembered. ‘In Ancient Greek.’

  Rachel nodded. ‘I don’t know its meaning. But I know it’s important. You have to hear it. It said: Perseus, you are not the hero.’

  I stared at her like she’d just slapped me. ‘You came thousands of miles to tell me I’m not the hero?’

  ‘It’s important,’ she insisted. ‘It will affect what you do.’

  ‘Not the hero of the prophecy?’ I asked. ‘Not the hero who defeats Kronos? What do you mean?’

  ‘I’m – I’m sorry, Percy. That’s all I know. I had to tell you because –’

  ‘Well!’ Chiron cantered over. ‘This must be Miss Dare.’

  I wanted to yell at him to go away, but of course I couldn’t. I tried to get my emotions under control. I felt like I had another personal hurricane swirling around me.

  ‘Chiron – Rachel Dare,’ I said. ‘Rachel – this is my teacher Chiron.’

  ‘Hello,’ Rachel said glumly. She didn’t look at all surprised that Chiron was a centaur.

  ‘You are not asleep, Miss Dare,’ he noticed. ‘And yet you are mortal?’

  ‘I’m mortal,’ she agreed, like it was a depressing thought. ‘The pilot fell asleep as soon as we passed the river. I don’t know why I didn’t. I just knew I had to be here, to warn Percy.’

  ‘Warn Percy?’

  ‘She’s been seeing things,’ I said. ‘Writing lines and making drawings.’

  Chiron raised an eyebrow. ‘Indeed? Tell me.’

  She told him the same things she’d told me.

  Chiron stroked his beard. ‘Miss Dare … perhaps we should talk.’

  ‘Chiron,’ I blurted. I had a sudden terrible image of Camp Half-Blood in the 1990s, and May Castellan’s scream coming from that attic. ‘You – you’ll help Rachel, right? I mean, you’ll warn her that she’s got to be careful with this stuff. Not go too far.’

  His tail flicked like it does when he’s anxious. ‘Yes, Percy. I will do my best to understand what is happening and advise Miss Dare, but this may take some time. Meanwhile, you should rest. We’ve moved your parents’ car to safety. The enemy seems to be staying put for now. We’ve set up bunks in the Empire State Building. Get some sleep.’

  ‘Everybody keeps telling me to sleep,’ I grumbled. ‘I don’t need sleep.’

  Chiron managed a smile. ‘Have you looked at yourself recently, Percy?’

  I glanced down at my clothes, which were scorched, burnt, sliced and tattered from my night of constant battles. ‘I look like death,’ I admitted. ‘But you think I can sleep after what just happened?’

  ‘You may be invulnerable in combat,’ Chiron chided, ‘but that only makes your body tire faster. I remember Achilles. Whenever that lad wasn’t fighting he was sleeping. He must’ve taken twenty naps a day. You, Percy, need your rest. You may be our only hope.’

  I wanted to complain that I wasn’t their only hope. According to Rachel, I wasn’t even the hero. But the look in Chiron’s eyes made it clear he wasn’t going to take no for an answer.

  ‘Sure,’ I grumbled. ‘Talk.’

  I trudged towards the Empire State Building. When I glanced back, Rachel and Chiron were walking together in earnest conversation, like they were discussing funeral arrangements.

  Inside the lobby, I found an empty bunk and collapsed, sure that I would never be able to sleep. A second later, my eyes closed.

  In my dreams, I was back in Hades’ garden. The Lord of the Dead paced up and down, holding his ears while Nico followed him, waving his arms.

  ‘You have to!’ Nico insisted.

  Demeter and Persephone sat behind them at the breakfast table. Both of the goddesses looked bored. Demeter poured shredded wheat into four huge bowls. Persephone was magically changing the flower arrangement on the table, turning the blossoms from red to yellow to polka-dotted.

  ‘I don’t have to do anything!’ Hades’ eyes blazed. ‘I’m a god!’

  ‘Father,’ Nico said, ‘if Olympus falls, your own palace’s safety doesn’t matter. You’ll fade, too.’

  ‘I am not an Olympian!’ he growled. ‘My family has made that quite clear.’

  ‘You are,’ Nico said. ‘Whether you like it or not.’

  ‘You saw what they did to your mother,’ Hades said. ‘Zeus killed her. And you would have me help them? They deserve what they get!’

  Persephone sighed. She walked her fingers across the table, absently turning the silverware into roses. ‘Could we please not talk about that woman?’

  ‘You know what would help this boy?’ Demeter mused. ‘Farming.’

  Persephone rolled her eyes. ‘Mother –’

  ‘Six months behind a plough. Excellent character building.’

  Nico stepped in front of his father, forcing Hades to face him. ‘My mother understood about family. That’s why she didn’t want to leave us. You can’t just abandon your family because they did something horrible. You’ve done horrible things to them, too.’

  ‘Maria died!’ Hades reminded him.

  ‘You can’t just cut yourself off from the other gods!’

  ‘I’ve done very well at it for thousands of years.’

  ‘And has that made you feel any better?’ Nico demanded. ‘Has that curse on the Oracle helped you at all? Holding grudges is a fatal flaw. Bianca warned me about that and she was right.’

  ‘For demigods! I am immortal, all powerful! I would not help the other gods if they begged me, if Percy Jackson himself pleaded –’

  ‘You’re just as much an outcast as I am!’ Nico yelled. ‘Stop being angry about it and do something helpful for once. That’s the only way they’ll respect you!’

  Hades’ palm filled with black fire.

  ‘Go ahead,’ Nico said. ‘Blast me. That’s just what the other gods would expect from you. Prove them right.’

  ‘Yes, please,’ Demeter complained. ‘Shut him up.’

  Persephone sighed. ‘Oh, I don’t know. I would rather fight in the war than eat another bowl of cereal. This is boring.’

  Hades roared in anger. His fireball hit a silver tree right next to Nico, melting it into a pool of liquid metal.

  And my dream changed.

  I was standing outside the United Nations, about a mile north-east of the Empire State Building. The Titan army had set up camp all around the UN complex. The flagpoles were hung with horrible trophies – helmets and armour pieces from defeated campers. All along First Avenue, giants sharpened their axes. Telkhines repaired armour at makeshift forges.

  Kronos himself paced at the top of the plaza, swinging his scythe so his dracaenae bodyguards stayed way back. Ethan Nakamura and Prometheus stood nearby, out of slicing range. Ethan was fidgeting with his shield straps, but Prometheus looked as calm and collected as ever in his tuxedo.

  ‘I hate this place,’ Kronos growled. ‘United Nations. As if mankind could ever unite. Remind me to tear down this building after we destroy Olympus.’

  ‘Yes, lord.’ Prometheus smiled as if his master’s anger amused him. ‘Shall we tear down the stables in Central Park, too? I know how much horses can annoy you.’

  ‘Don’t mock me, Prometheus! Those cursed centaurs will be sorry they interfered. I will feed them to the hellhounds, starting with that son of mine – that weakling Chiron.’

  Prometheus shrugged. ‘That weakling destroyed an entire legion of telkhines with his arrows.’

/>   Kronos swung his scythe and cut a flagpole in half. The national colours of Brazil toppled into the army, squashing a dracaena.

  ‘We will destroy them!’ Kronos roared. ‘It is time to unleash the drakon. Nakamura – you will do this.’

  ‘Y-yes, lord. At sunset?’

  ‘No,’ Kronos said. ‘Immediately. The defenders of Olympus are badly wounded. They will not expect a quick attack. Besides, we know this drakon they cannot beat.’

  Ethan looked confused. ‘My lord?’

  ‘Never you mind, Nakamura. Just do my bidding. I want Olympus in ruins by the time Typhon reaches New York. We will break the gods utterly!’

  ‘But, my lord,’ Ethan said. ‘Your regeneration.’

  Kronos pointed at Ethan and the demigod froze.

  ‘Does it seem,’ Kronos hissed, ‘that I need to regenerate?’

  Ethan didn’t respond. Kind of hard to do when you’re immobilized in time.

  Kronos snapped his fingers and Ethan collapsed.

  ‘Soon,’ the Titan growled, ‘this form will be unnecessary. I will not rest with victory so close. Now go!’

  Ethan scrambled away.

  ‘This is dangerous, my lord,’ Prometheus warned. ‘Do not be hasty.’

  ‘Hasty? After festering for three thousand years in the depths of Tartarus, you call me hasty? I will slice Percy Jackson into a thousand pieces.’

  ‘Thrice you’ve fought him,’ Prometheus pointed out. ‘And yet you’ve always said it is beneath the dignity of a Titan to fight a mere mortal. I wonder if your mortal host is influencing you, weakening your judgement.’

  Kronos turned his golden eyes on the other Titan. ‘You call me weak?’

  ‘No, my lord. I only meant –’

  ‘Are your loyalties divided?’ Kronos asked. ‘Perhaps you miss your old friends, the gods. Would you like to join them?’ Prometheus paled. ‘I misspoke, my lord. Your orders will be carried out.’ He turned to the armies and shouted: ‘PREPARE FOR BATTLE!’

  The troops began to stir.

  From somewhere behind the UN compound, an angry roar shook the city – the sound of a drakon waking. The noise was so horrible it woke me, and I realized I could still hear it from a mile away.

  Grover stood next to me, looking nervous. ‘What was that?’

  ‘They’re coming,’ I told him. ‘And we’re in trouble.’

  The Hephaestus cabin was out of Greek fire. The Apollo cabin and the Hunters were scrounging for arrows. Most of us had already ingested so much ambrosia and nectar we didn’t dare take any more.

  We had sixteen campers, fifteen Hunters and half a dozen satyrs left in fighting shape. The rest had taken refuge on Olympus. The Party Ponies tried to form ranks, but they staggered and giggled and they all smelled like root beer. The Texans were head-butting the Coloradoans. The Missouri branch was arguing with Illinois. The chances were pretty good the whole army would end up fighting each other rather than the enemy.

  Chiron trotted up with Rachel on his back. I felt a twinge of annoyance, because Chiron rarely gave anyone a ride, and never a mortal.

  ‘Your friend here has some useful insights, Percy,’ he said.

  Rachel blushed. ‘Just some things I saw in my head.’

  ‘A drakon,’ Chiron said. ‘A Lydian drakon, to be exact. The oldest and most dangerous kind.’

  I stared at her. ‘How did you know that?’

  ‘I’m not sure,’ Rachel admitted. ‘But this drakon has a particular fate. It will be killed by a child of Ares.’

  Annabeth crossed her arms. ‘How can you possibly know that?’

  ‘I just saw it. I can’t explain.’

  ‘Well, let’s hope you’re wrong,’ I said. ‘Because we’re a little short on children of Ares …’ A horrible thought occurred to me, and I cursed in Ancient Greek.

  ‘What?’ Annabeth asked.

  ‘The spy,’ I told her. ‘Kronos said, “We know they cannot beat this drakon.” The spy has been keeping him updated. Kronos knows the Ares cabin isn’t with us. He intentionally picked a monster we can’t kill.’

  Thalia scowled. ‘If I ever catch your spy, he’s going to be very sorry. Maybe we could send another messenger to camp –’

  ‘I’ve already done it,’ Chiron said. ‘Blackjack is on his way. But if Silena wasn’t able to convince Clarisse, I doubt Blackjack will be able –’

  A roar shook the ground. It sounded very close.

  ‘Rachel,’ I said, ‘get inside the building.’

  ‘I want to stay.’

  A shadow blotted out the sun. Across the street, the drakon slithered down the side of a skyscraper. It roared and a thousand windows shattered.

  ‘On second thoughts,’ Rachel said in a small voice, ‘I’ll be inside.’

  Let me explain: there are dragons, and then there are drakons.

  Drakons are several millennia older than dragons, and much larger. They look like giant serpents. Most don’t have wings. Most don’t breathe fire (though some do). All are poisonous. All are immensely strong, with scales harder than titanium. Their eyes can paralyse you – not the turn you to stone Medusa-type paralysis, but the oh my gods that big snake is going to eat me type of paralysis, which is just as bad.

  We have drakon-fighting classes at camp, but there is no way to prepare yourself for a fifty-metre-long serpent as thick as a school bus slithering down the side of a building, its yellow eyes like searchlights and its mouth full of razor-sharp teeth big enough to chew elephants.

  It almost made me long for the flying pig.

  Meanwhile, the enemy army advanced down Fifth Avenue. We’d done our best to push cars out of the way to keep the mortals safe, but that just made it easier for our enemies to approach. The Party Ponies swished their tails nervously. Chiron galloped up and down their ranks, shouting encouragement to stand tough and think about victory and root beer, but I figured any second they would panic and run.

  ‘I’ll take the drakon.’ My voice came out as a timid squeak. Then I yelled louder: ‘I’LL TAKE THE DRAKON! Everyone else, hold the line against the army!’

  Annabeth stood next to me. She had pulled her owl helmet low over her face, but I could tell her eyes were red.

  ‘Will you help me?’ I asked.

  ‘That’s what I do,’ she said miserably. ‘I help my friends.’

  I felt like a complete jerk. I wanted to pull her aside and explain that I didn’t mean for Rachel to be here, that it wasn’t my idea, but we had no time.

  ‘Go invisible,’ I said. ‘Look for weak links in its armour while I keep it busy. Just be careful.’

  I whistled. ‘Mrs O’Leary, heel!’

  ‘ROOOF!’ My hellhound leaped over a line of centaurs and gave me a kiss that smelled suspiciously of pepperoni pizza.

  I drew my sword and we charged the monster.

  The drakon was three stories above us, slithering sideways along the building as it sized up our forces. Wherever it looked, centaurs froze in fear.

  From the north, the enemy army crashed into the Party Ponies and our lines broke. The drakon lashed out, swallowing three Californian centaurs in one gulp before I could even get close.

  Mrs O’Leary launched herself through the air – a deadly black shadow with teeth and claws. Normally, a pouncing hellhound is a terrifying sight, but next to the drakon Mrs O’Leary looked like a child’s night-night doll.

  Her claws raked harmlessly off the drakon’s scales. She bit the monster’s throat, but couldn’t make a dent. Her weight, however, was enough to knock the drakon off the side of the building. It flailed awkwardly and crashed to the sidewalk – hellhound and serpent twisting and thrashing. The drakon tried to bite Mrs O’Leary, but she was too close to the serpent’s mouth. Poison spewed everywhere, melting centaurs into dust along with quite a few monsters, but Mrs O’Leary weaved around the serpent’s head, scratching and biting.

  ‘YAAAH!’ I plunged Riptide deep into the monster’s left eye. The spotlight went dark. The
drakon hissed and reared back to strike, but I rolled aside.

  It bit a swimming-pool-sized chunk out of the pavement. It turned towards me with its good eye and I focused on its teeth so I wouldn’t get paralysed. Mrs O’Leary did her best to cause a distraction. She leaped onto the serpent’s head and scratched and growled like a really angry black wig.

  The rest of the battle wasn’t going well. Centaurs panicked under the onslaught of giants and demons. An occasional orange camp T-shirt appeared in the sea of fighting, but it quickly disappeared. Arrows screamed. Fire exploded in waves across both armies, but the action was moving across the street to the entrance of the Empire State Building. We were losing ground.

  Suddenly Annabeth materialized on the drakon’s back. Her invisibility cap rolled off her head as she drove her bronze knife between a chink in the serpent’s scales.

  The drakon roared. It coiled around, knocking Annabeth off its back.

  I reached her just as she hit the ground. I dragged her out of the way as the serpent rolled, crushing a lamppost right where she’d been.

  ‘Thanks,’ she said.

  ‘I told you to be careful!’

  ‘Yeah, well – DUCK!’

  It was her turn to save me. She tackled me as the monster’s teeth snapped above my head. Mrs O’Leary body-slammed the drakon’s face to get its attention and we rolled out of the way.

  Meanwhile, our allies had retreated to the doors of the Empire State Building. The entire enemy army was surrounding them.

  We were out of options. No more help was coming. Annabeth and I would have to retreat before we were cut off from Mount Olympus.

  Then I heard a rumbling in the south. It wasn’t a sound you hear much in New York, but I recognized it immediately: chariot wheels.

  A girl’s voice yelled, ‘ARES!’

  And a dozen war chariots charged into battle. Each flew a red banner with the symbol of the wild boar’s head. Each was pulled by a team of skeletal horses with manes of fire. A total of thirty fresh warriors, armour gleaming and eyes full of hate, lowered their lances as one – making a bristling wall of death.