But, before he could strike, all the arai in front of him exploded into dust.

x.x.xII.

PERCY.

BOB SERIOUSLY KNEW HOW TO USE A BROOM.

He slashed back and forth, destroying the demons one after the other while Small Bob the kitten sat on his shoulder, arching its back and hissing.

In a matter of seconds, the arai were gone. Most had been vaporized. The smart ones had flown off into the darkness, shrieking in terror.

Percy wanted to thank the t.i.tan, but his voice wouldn't work. His legs buckled. His ears rang. Through a red glow of pain, he saw Annabeth a few yards away, wandering blindly towards the edge of the cliff.

'Uh!' Percy grunted.

Bob followed his gaze. He bounded towards Annabeth and scooped her up. She yelled and kicked, pummelling Bob's gut, but Bob didn't seem to care. He carried her over to Percy and put her down gently.

The t.i.tan touched her forehead. 'Owie.'

Annabeth stopped fighting. Her eyes cleared. 'Where what ?'

She saw Percy, and a series of expressions flashed across her face relief, joy, shock, horror. 'What's wrong with him?' she cried. 'What happened?'

She cradled his shoulders and wept into his scalp.

Percy wanted to tell her it was okay, but of course it wasn't. He couldn't even feel his body any more. His consciousness was like a small helium balloon, loosely tied to the top of his head. It had no weight, no strength. It just kept expanding, getting lighter and lighter. He knew that soon it would either burst or the string would break, and his life would float away.

Annabeth took his face in her hands. She kissed him and tried to wipe the dust and sweat from his eyes.

Bob loomed over them, his broom planted like a flag. His face was unreadable, luminously white in the dark.

'Lots of curses,' Bob said. 'Percy has done bad things to monsters.'

'Can you fix him?' Annabeth pleaded. 'Like you did with my blindness? Fix Percy!'

Bob frowned. He picked at the name tag on his uniform like it was a scab.

Annabeth tried again. 'Bob '

'Iapetus,' Bob said, his voice a low rumble. 'Before Bob. It was Iapetus.'

The air was absolutely still. Percy felt helpless, barely connected to the world.

'I like Bob better.' Annabeth's voice was surprisingly calm. 'Which do you like?'

The t.i.tan regarded her with his pure silver eyes. 'I do not know any more.'

He crouched next to her and studied Percy. Bob's face looked haggard and careworn, as if he suddenly felt the weight of all his centuries.

'I promised,' he murmured. 'Nico asked me to help. I do not think Iapetus or Bob likes breaking promises.' He touched Percy's forehead.

'Owie,' the t.i.tan murmured. 'Very big owie.'

Percy sank back into his body. The ringing in his ears faded. His vision cleared. He still felt like he had swallowed a deep fryer. His insides bubbled. He could sense that the poison had only been slowed, not removed.

But he was alive.

He tried to meet Bob's eyes, to express his grat.i.tude. His head lolled against his chest.

'Bob cannot cure this,' Bob said. 'Too much poison. Too many curses piled up.'

Annabeth hugged Percy's shoulders. He wanted to say: I can feel that now. Ow. Too tight.

'What can we do, Bob?' Annabeth asked. 'Is there water anywhere? Water might heal him.'

'No water,' Bob said. 'Tartarus is bad.'

I noticed, Percy wanted to yell.

At least the t.i.tan called himself Bob. Even if he blamed Percy for taking his memory, maybe he would help Annabeth if Percy didn't make it.

'No,' Annabeth insisted. 'No, there has to be a way. Something to heal him.'

Bob placed his hand on Percy's chest. A cold tingle like eucalyptus oil spread across his sternum, but as soon as Bob lifted his hand the relief stopped. Percy's lungs felt as hot as lava again.

'Tartarus kills demiG.o.ds,' Bob said. 'It heals monsters, but you do not belong. Tartarus will not heal Percy. The pit hates your kind.'

'I don't care,' Annabeth said. 'Even here, there has to be someplace he can rest, some kind of cure he can take. Maybe back at the altar of Hermes, or '

In the distance, a deep voice bellowed a voice that Percy recognized, unfortunately.

'I SMELL HIM!' roared the giant. 'BEWARE, SON OF POSEIDON! I COME FOR YOU!'

'Polybotes,' Bob said. 'He hates Poseidon and his children. He is very close now.'

Annabeth struggled to get Percy to his feet. He hated making her work so hard, but he felt like a sack of billiard b.a.l.l.s. Even with Annabeth supporting almost all his weight, he could barely stand.

'Bob, I'm going on, with or without you,' she said. 'Will you help?'

The kitten Small Bob mewed and began to purr, rubbing against Bob's chin.

Bob looked at Percy, and Percy wished he could read the t.i.tan's expression. Was he angry or just thoughtful? Was he planning revenge, or was he just feeling hurt because Percy had lied about being his friend?

'There is one place,' Bob said at last. 'There is a giant who might know what to do.'

Annabeth almost dropped Percy. 'A giant. Uh, Bob, giants are bad.'

'One is good,' Bob insisted. 'Trust me, and I will take you ... unless Polybotes and the others catch us first.'

x.x.xIII.

JASON.

JASON FELL ASLEEP ON THE JOB. Which was bad, since he was a thousand feet in the air.

He should have known better. It was the morning after their encounter with Sciron the bandit, and Jason was on duty, fighting some wild venti who were threatening the ship. When he slashed through the last one, he forgot to hold his breath.

A stupid mistake. When a wind spirit disintegrates, it creates a vacuum. Unless you're holding your breath, the air gets sucked right out of your lungs. The pressure in your inner ears drops so fast that you black out.

That's what happened to Jason.

Even worse, he instantly plunged into a dream. In the back of his subconscious, he thought: Really? Now?

He needed to wake up or he would die, but he wasn't able to hold on to that thought. In the dream, he found himself on the roof of a tall building, the night-time skyline of Manhattan spread around him. A cold wind whipped through his clothes.

A few blocks away, clouds gathered above the Empire State Building the entrance to Mount Olympus itself. Lightning flashed. The air was metallic with the smell of oncoming rain. The top of the skysc.r.a.per was lit up as usual, but the lights seemed to be malfunctioning. They flickered from purple to orange as if the colours were fighting for dominance.

On the roof of Jason's building stood his old comrades from Camp Jupiter: an array of demiG.o.ds in combat armour, their Imperial gold weapons and shields glinting in the dark. He saw Dakota and Nathan, Leila and Marcus. Octavian stood to one side, thin and pale, his eyes red-rimmed from sleeplessness or anger, a string of sacrificial stuffed animals around his waist. His augur's white robe was draped over a purple T-shirt and cargo pants.

In the centre of the line stood Reyna, her metal dogs Aurum and Argentum at her side. Upon seeing her, Jason felt an incredible pang of guilt. He'd let her believe they had a future together. He had never been in love with her, and he hadn't led her on, exactly ... but he also hadn't shut her down.

He'd disappeared, leaving her to run the camp on her own. (Okay, that hadn't exactly been Jason's idea, but still ...) Then he had returned to Camp Jupiter with his new girlfriend Piper and a whole bunch of Greek friends in a warship. They'd fired on the Forum and run away, leaving Reyna with a war on her hands.

In his dream she looked tired. Others might not notice, but he'd worked with her long enough to recognize the weariness in her eyes, the tightness in her shoulders under the straps of her armour. Her dark hair was wet, like she'd taken a hasty shower.

The Romans stared at the roof-access door as if they were waiting for someone.

When the door opened, two people emerged. One was a faun no, Jason thought a satyr. He'd learned the difference at Camp Half-Blood, and Coach Hedge was always correcting him if he made that mistake. Roman fauns tended to hang around and beg and eat. Satyrs were more helpful, more engaged with demiG.o.d affairs. Jason didn't think he'd seen this particular satyr before, but he was sure the guy was from the Greek side. No faun would look so purposeful walking up to an armed group of Romans in the middle of the night.

He wore a green Nature Conservancy T-shirt with pictures of endangered whales and tigers and stuff. Nothing covered his s.h.a.ggy legs and hooves. He had a bushy goatee, curly brown hair tucked into a Rasta-style cap and a set of reed pipes around his neck. His hands fidgeted with the hem of his shirt, but considering the way he studied the Romans, noting their positions and their weapons, Jason figured this satyr had been in combat before.

At his side was a red-headed girl Jason recognized from Camp Half-Blood their oracle, Rachel Elizabeth Dare. She had long frizzy hair, a plain white blouse and jeans covered with hand-drawn ink designs. She held a blue plastic hairbrush that she tapped nervously against her thigh like a good luck talisman.

Jason remembered her at the campfire, reciting lines of prophecy that sent Jason, Piper and Leo on their first quest together. She was a regular mortal teenager not a demiG.o.d but, for reasons Jason never understood, the spirit of Delphi had chosen her as its host.

The real question: What was she doing with the Romans?

She stepped forward, her eyes fixed on Reyna. 'You got my message.'

Octavian snorted. 'That's the only reason you made it this far alive, Graecus. I hope you've come to discuss surrender terms.'

'Octavian ...' Reyna warned.

'At least search them!' Octavian protested.

'No need,' Reyna said, studying Rachel Dare. 'Do you bring weapons?'

Rachel shrugged. 'I hit Kronos in the eye with this hairbrush once. Otherwise, no.'

The Romans didn't seem to know what to make of that. The mortal didn't sound like she was kidding.

'And your friend?' Reyna nodded to the satyr. 'I thought you were coming alone.'

'This is Grover Underwood,' Rachel said. 'He's a leader of the Council.'

'What council?' Octavian demanded.

'Cloven Elders, man.' Grover's voice was high and reedy, as if he were terrified, but Jason suspected the satyr had more steel than he let on. 'Seriously, don't you Romans have nature and trees and stuff? I've got some news you need to hear. Plus, I'm a card-carrying protector. I'm here to, you know, protect Rachel.'

Reyna looked like she was trying not to smile. 'But no weapons?'

'Just the pipes.' Grover's expression became wistful. 'Percy always said my cover of "Born to be Wild" should count as a dangerous weapon, but I don't think it's that bad.'

Octavian sneered. 'Another friend of Percy Jackson. That's all I need to hear.'

Reyna held up her hand for silence. Her gold and silver dogs sniffed the air, but they remained calm and attentive at her side.

'So far, our guests speak the truth,' Reyna said. 'Be warned, Rachel and Grover, if you start to lie, this conversation will not go well for you. Say what you came to say.'

From her jeans pocket, Rachel dug out a piece of paper like a napkin. 'A message. From Annabeth.'

Jason wasn't sure he'd heard her right. Annabeth was in Tartarus. She couldn't send anyone a note on a napkin.

Maybe I've hit the water and died, his subconscious said. This isn't a real vision. It's some sort of after-death hallucination.