On the left side of the courtyard stood a line of columns holding up weathered grey arches. On the right side was a white marble building with rows of tall windows.

'The peristyle,' Nico said. 'This was the entrance to Diocletian's private residence.' He scowled at Jason. 'And, please, I don't like being touched. Don't ever grab me again.'

Jason's shoulder blades tensed. He thought he heard the undertone of a threat, like: unless you want to get a Stygian sword up your nose. 'Uh, okay. Sorry. How do you know what this place is called?'

Nico scanned the atrium. He focused on some steps in the far corner, leading down.

'I've been here before.' His eyes were as dark as his blade. 'With my mother and Bianca. A weekend trip from Venice. I was maybe ... six?'

'That was when ... the 1930s?'

''Thirty-eight or so,' Nico said absently. 'Why do you care? Do you see that winged guy anywhere?'

'No ...' Jason was still trying to wrap his mind around Nico's past.

Jason always tried to build a good relationship with the people on his team. He'd learned the hard way that if somebody was going to have your back in a fight it was better if you found some common ground and trusted each other. But Nico wasn't easy to figure out. 'I just ... I can't imagine how weird that must be, coming from another time.'

'No, you can't.' Nico stared at the stone floor. He took a deep breath.

'Look ... I don't like talking about it. Honestly, I think Hazel has it worse. She remembers more about when she was young. She had to come back from the dead and adjust to the modern world. Me ... me and Bianca, we were stuck at the Lotus Hotel. Time pa.s.sed so quickly. In a weird way, that made the transition easier.'

'Percy told me about that place,' Jason said. 'Seventy years, but it only felt like a month?'

Nico clenched his fist until his fingers turned white. 'Yeah. I'm sure Percy told you all about me.'

His voice was heavy with bitterness more than Jason could understand. He knew that Nico had blamed Percy for getting his sister Bianca killed, but they'd supposedly got past that, at least according to Percy. Piper had also mentioned a rumour that Nico had a crush on Annabeth. Maybe that was part of it.

Still ... Jason didn't get why Nico pushed people away, why he never spent much time at either camp, why he preferred the dead to the living. He really didn't get why Nico had promised to lead the Argo II to Epirus if he hated Percy Jackson so much.

Nico's eyes swept the windows above them. 'Roman dead are everywhere here ... Lares. Lemures. They're watching. They're angry.'

'At us?' Jason's hand went to his sword.

'At everything.' Nico pointed to a small stone building on the west end of the courtyard. 'That used to be a temple to Jupiter. The Christians changed it to a baptistery. The Roman ghosts don't like that.'

Jason stared at the dark doorway.

He'd never met Jupiter, but he thought of his father as a living person the guy who'd fallen in love with his mom. Of course he knew his dad was immortal, but somehow the full meaning of that had never really sunk in until now as he stared at a doorway Romans had walked through, thousands of years ago, to worship his dad. The idea gave Jason a splitting headache.

'And over there ...' Nico pointed east to a hexagonal building ringed with freestanding columns. 'That was the mausoleum of the emperor.'

'But his tomb isn't there any more,' Jason guessed.

'Not for centuries,' Nico said. 'When the empire collapsed, the building was turned into a Christian cathedral.'

Jason swallowed. 'So if Diocletian's ghost is still around here '

'He's probably not happy.'

The wind rustled, pushing leaves and food wrappers across the peristyle. In the corner of his eye, Jason caught a glimpse of movement a blur of red and gold.

When he turned, a single rust-coloured feather was settling on the steps that led down.

'That way.' Jason pointed. 'The winged guy. Where do you think those stairs lead?'

Nico drew his sword. His smile was even more unsettling than his scowl. 'Underground,' he said. 'My favourite place.'

Underground was not Jason's favourite place.

Ever since his trip beneath Rome with Piper and Percy, fighting those twin giants in the hypogeum under the Colosseum, most of his nightmares had been about bas.e.m.e.nts, trapdoors and large hamster-wheels.

Having Nico along was not rea.s.suring. His Stygian iron blade seemed to make the shadows even gloomier, as if the infernal metal were drawing the light and heat out of the air.

They crept through a vast cellar with thick support columns holding up a vaulted ceiling. The limestone blocks were so old they had fused together from centuries of moisture, making the place look almost like a naturally formed cave.

None of the tourists had ventured down here. Obviously, they were smarter than demiG.o.ds.

Jason drew his gladius. They made their way under the low archways, their steps echoing on the stone floor. Barred windows lined the top of one wall, facing the street level, but that just made the cellar feel more claustrophobic. The shafts of sunlight looked like slanted prison bars, swirling with ancient dust.

Jason pa.s.sed a support beam, looked to his left and almost had a heart attack. Staring right at him was a marble bust of Diocletian, his limestone face glowering with disapproval.

Jason steadied his breathing. This seemed like a good place to leave the note he'd written for Reyna, telling her of their route to Epirus. It was away from the crowds, but he trusted Reyna would find it. She had the instincts of a hunter. He slipped the note between the bust and its pedestal and stepped back.

Diocletian's marble eyes made him jumpy. Jason couldn't help thinking of Terminus, the talking statue-G.o.d back at New Rome. He hoped Diocletian wouldn't bark at him or suddenly burst into song.

'h.e.l.lo!'

Before Jason could register that the voice had come from somewhere else, he sliced off the emperor's head. The bust toppled and shattered against the floor.

'That wasn't very nice,' said the voice behind them.

Jason turned. The winged man from the ice-cream stand was leaning against a nearby column, casually tossing a small bronze hoop in the air. At his feet sat a wicker picnic basket full of fruit.

'I mean,' the man said, 'what did Diocletian ever do to you?'

The air swirled around Jason's feet. The shards of marble gathered into a miniature tornado, spiralled back to the pedestal and rea.s.sembled into a complete bust, the note still tucked underneath.

'Uh ' Jason lowered his sword. 'It was an accident. You startled me.'

The winged dude chuckled. 'Jason Grace, the West Wind has been called many things ... warm, gentle, life-giving and devilishly handsome. But I have never been called startling. I leave that cra.s.s behaviour to my gusty brethren in the north.'

Nico inched backwards. 'The West Wind? You mean you're '

'Favonius,' Jason realized. 'G.o.d of the West Wind.'

Favonius smiled and bowed, obviously pleased to be recognized. 'You can call me by my Roman name, certainly, or Zephyros, if you're Greek. I'm not hung up about it.'

Nico looked pretty hung up about it. 'Why aren't your Greek and Roman sides in conflict, like the other G.o.ds?'

'Oh, I have the occasional headache.' Favonius shrugged. 'Some mornings I'll wake up in a Greek chiton when I'm sure I went to sleep in my SPQR pyjamas. But mostly the war doesn't bother me. I'm a minor G.o.d, you know never really been much in the limelight. The to-and-fro battles among you demiG.o.ds don't affect me as greatly.'

'So ...' Jason wasn't quite sure whether to sheathe his sword. 'What are you doing here?'

'Several things!' Favonius said. 'Hanging out with my basket of fruit. I always carry a basket of fruit. Would you like a pear?'

'I'm good. Thanks.'

'Let's see ... earlier I was eating ice cream. Right now I'm tossing this quoit ring.' Favonius spun the bronze hoop on his index finger.

Jason had no idea what a quoit was, but he tried to stay focused. 'I mean why did you appear to us? Why did you lead us to this cellar?'

'Oh!' Favonius nodded. 'The sarcophagus of Diocletian. Yes. This was its final resting place. The Christians moved it out of the mausoleum. Then some barbarians destroyed the coffin. I just wanted to show you ' he spread his hands sadly 'that what you're looking for isn't here. My master has taken it.'

'Your master?' Jason had a flashback to a floating palace above Pike's Peak in Colorado, where he'd visited (and barely survived) the studio of a crazy weatherman who claimed he was the G.o.d of all the winds. 'Please tell me your master isn't Aeolus.'

'That airhead?' Favonius snorted. 'No, of course not.'

'He means Eros.' Nico's voice turned edgy. 'Cupid, in Latin.'

Favonius smiled. 'Very good, Nico di Angelo. I'm glad to see you again, by the way. It's been a long time.'

Nico knitted his eyebrows. 'I've never met you.'

'You've never seen me,' the G.o.d corrected. 'But I've been watching you. When you came here as a small boy, and several times since. I knew eventually you would return to look upon my master's face.'

Nico turned even paler than usual. His eyes darted around the cavernous room as if he was starting to feel trapped.

'Nico?' Jason said. 'What's he talking about?'

'I don't know. Nothing.'

'Nothing?' Favonius cried. 'The one you care for most ... plunged into Tartarus, and still you will not allow the truth?'

Suddenly Jason felt like he was eavesdropping.

The one you care for most.

He remembered what Piper had told him about Nico's crush on Annabeth. Apparently Nico's feelings went way deeper than a simple crush.

'We've only come for Diocletian's sceptre,' Nico said, clearly anxious to change the subject. 'Where is it?'

'Ah ...' Favonius nodded sadly. 'You thought it would be as easy as facing Diocletian's ghost? I'm afraid not, Nico. Your trials will be much more difficult. You know, long before this was Diocletian's Palace, it was the gateway to my master's court. I've dwelt here for aeons, bringing those who sought love into the presence of Cupid.'

Jason didn't like the mention of difficult trials. He didn't trust this weird G.o.d with the hoop and the wings and the basket of fruit. But an old story surfaced in his mind something he'd heard at Camp Jupiter. 'Like Psyche, Cupid's wife. You carried her to his palace.'

Favonius's eyes twinkled. 'Very good, Jason Grace. From this exact spot, I carried Psyche on the winds and brought her to the chambers of my master. In fact, that is why Diocletian built his palace here. This place has always been graced by the gentle West Wind.' He spread his arms. 'It is a spot of tranquillity and love in a turbulent world. When Diocletian's Palace was ransacked '

'You took the sceptre,' Jason guessed.

'For safekeeping,' Favonius agreed. 'It is one of Cupid's many treasures, a reminder of better times. If you want it ...' Favonius turned to Nico. 'You must face the G.o.d of love.'

Nico stared at the sunlight coming through the windows, as if wishing he could escape through those narrow openings.

Jason wasn't sure what Favonius wanted, but if facing the G.o.d of love meant forcing Nico into some sort of confession about which girl he liked, that didn't seem so bad.

'Nico, you can do this,' Jason said. 'It might be embarra.s.sing, but it's for the sceptre.'

Nico didn't look convinced. In fact he looked like he was going to be sick. But he squared his shoulders and nodded. 'You're right. I I'm not afraid of a love G.o.d.'

Favonius beamed. 'Excellent! Would you like a snack before you go?' He plucked a green apple from his basket and frowned at it. 'Oh, bl.u.s.ter. I keep forgetting my symbol is a basket of unripe fruit. Why doesn't the spring wind get more credit? Summer has all the fun.'

'That's okay,' Nico said quickly. 'Just take us to Cupid.'

Favonius spun the hoop on his finger, and Jason's body dissolved into air.

x.x.xVI.

JASON.

JASON HAD RIDDEN THE WIND MANY TIMES. Being the wind was not the same.

He felt out of control, his thoughts scattered, no boundaries between his body and the rest of the world. He wondered if this was how monsters felt when they were defeated bursting into dust, helpless and formless.

Jason could sense Nico's presence nearby. The West Wind carried them into the sky above Split. Together they raced over the hills, past Roman aqueducts, highways and vineyards. As they approached the mountains, Jason saw the ruins of a Roman town spread out in a valley below crumbling walls, square foundations and cracked roads, all overgrown with gra.s.s so it looked like a giant, mossy game board.

Favonius set them down in the middle of the ruins, next to a broken column the size of a redwood.

Jason's body re-formed. For a moment it felt even worse than being the wind, like he'd suddenly been wrapped in a lead overcoat.

'Yes, mortal bodies are terribly bulky,' Favonius said, as if reading his thoughts. The wind G.o.d settled on a nearby wall with his basket of fruit and spread his russet wings in the sun. 'Honestly, I don't know how you stand it, day in and day out.'

Jason scanned their surroundings. The town must have been huge once. He could make out the sh.e.l.ls of temples and bathhouses, a half-buried amphitheatre and empty pedestals that must have once held statues. Rows of columns marched off to nowhere. The old city walls weaved in and out of the hillside like stone thread through a green cloth.

Some areas looked like they'd been excavated, but most of the city just seemed abandoned, as if it had been left to the elements for the last two thousand years.

'Welcome to Salona,' Favonius said. 'Capital of Dalmatia! Birthplace of Diocletian! But before that, long before that, it was the home of Cupid.'