The Son of Neptune

large that Hazel got vertigo just trying to take it all in. The side was riddled with crevices and caves, spiked with jagged ridges like axe blades. Pieces were constantly crumbling off – some no larger than snowballs, some the size of houses.

When they were about fifty yards from the base, a thunderclap rattled Hazel’s bones, and a curtain of ice that would have covered Camp Jupiter calved away and fell towards them.

‘Look out!’ Frank shouted, which seemed a little unnecessary to Hazel.

Arion was way ahead of him. In a burst of speed, he zigzagged through the debris, leaping over chunks of ice and clambering up the face of the glacier.

Percy and Frank both cussed like horses and held on desperately while Hazel wrapped her arms round Arion’s neck. Somehow, they managed not to fall off as Arion scaled the cliffs, jumping from foothold to foothold with impossible speed and agility. It was like falling down a mountain in reverse.

Then it was over. Arion stood proudly at the top of a ridge of ice that loomed over the void. The sea was now three hundred feet below them.

Arion whinnied a challenge that echoed off the mountains. Percy didn’t translate, but Hazel was pretty sure Arion was calling out to any other horses that might be in the bay: Beat that, ya punks!

Then he turned and ran inland across the top of the glacier, leaping a chasm fifty feet across.

‘There!’ Percy pointed.

The horse stopped. Ahead of them stood a frozen Roman camp like a giant-sized ghastly replica of Camp Jupiter. The trenches bristled with ice spikes. The snow-brick ramparts glared blinding white. Hanging from the guard towers, banners of frozen blue cloth shimmered in the Arctic sun.

There was no sign of life. The gates stood wide open. No sentries walked the walls. Still, Hazel had an uneasy feeling in her gut. She remembered the cave in Resurrection Bay where she’d worked to raise Alcyoneus – the oppressive sense of malice and the constant boom, boom, boom, like Gaia’s heartbeat. This place felt similar, as if the earth were trying to wake up and consume everything – as if the mountains on either side wanted to crush them and the entire glacier to pieces.

Arion trotted skittishly.

‘Frank,’ Percy said, ‘how about we go on foot from here?’

Frank sighed with relief. ‘Thought you’d never ask.’

They dismounted and took some tentative steps. The ice seemed stable, covered with a fine carpet of snow so that it wasn’t too slippery.

Hazel urged Arion forward. Percy and Frank walked on either side, sword and bow ready. They approached the gates without being challenged. Hazel was trained to spot pits, snares, trip lines and all sorts of other traps Roman legions had faced for aeons in enemy territory, but she saw nothing – just the yawning icy gates and the frozen banners crackling in the wind.

She could see straight down the Via Praetoria. At the crossroads, in front of the snow-brick principia, a tall, dark-robed figure stood, bound in icy chains.

‘Thanatos,’ Hazel murmured.

She felt as if her soul were being pulled forward, drawn towards Death like dust towards a vacuum. Her vision went dark. She almost fell off Arion, but Frank caught her and propped her up.

‘We’ve got you,’ he promised. ‘Nobody’s taking you away.’

Hazel gripped his hand. She didn’t want to let go. He was so solid, so reassuring, but Frank couldn’t protect her from Death. His own life was as fragile as a half-burnt piece of wood.

‘I’m all right,’ she lied.

Percy looked around uneasily. ‘No defenders? No giant? This has to be a trap.’

‘Obviously,’ Frank said. ‘But I don’t think we have a choice.’

Before Hazel could change her mind, she urged Arion through the gates. The layout was so familiar – cohort barracks, baths, armoury. It was an exact replica of Camp Jupiter, except three times as big. Even on horseback, Hazel felt tiny and insignificant, as if they were moving through a model city constructed by the gods.

They stopped ten feet from the robed figure.

Now that she was here, Hazel felt a reckless urge to finish the quest. She knew she was in more danger than when she’d been fighting the Amazons, or fending off the gryphons, or climbing the glacier on Arion’s back. Instinctively she knew that Thanatos could simply touch her, and she would die.

But she also had a feeling that if she didn’t see the quest through, if she didn’t face her fate bravely, she would still die – in cowardice and failure. The judges of the dead wouldn’t be lenient to her a second time.

Arion cantered back and forth, sensing her disquiet.

‘Hello?’ Hazel forced out the word. ‘Mr Death?’

The hooded figure raised his head.

Instantly, the whole camp stirred to life. Figures in Roman armour emerged from the barracks, the principia, the armoury and the canteen, but they weren’t human. They were shades – the chattering ghosts Hazel had lived with for decades in the Fields of Asphodel. Their bodies weren’t much more than wisps of black vapour, but they managed to hold together sets of scale armour, greaves and helmets. Frost-covered swords were strapped to their waists. Pila and dented shields floated in their smoky hands. The plumes on the centurions’ helmets were frozen and ragged. Most of the shades were on foot, but two soldiers burst out of the stables in a golden chariot pulled by ghostly black steeds.

When Arion saw the horses, he stamped the ground in outrage.

Frank gripped his bow. ‘Yep, here’s the trap.’

XLIV Hazel

THE GHOSTS FORMED RANKS AND ENCIRCLED the crossroads. There were about a hundred in all – not an entire legion, but more than a cohort. Some carried the tattered lightning-bolt banners of the Twelfth Legion, Fifth Cohort – Michael Varus’s doomed expedition from the 1980s. Others carried standards and insignia Hazel didn’t recognize, as if they’d died at different times, on different quests – maybe not even from Camp Jupiter.

Most were armed with Imperial gold weapons – more Imperial gold than the entire Twelfth Legion possessed. Hazel could feel the combined power of all that gold humming around her, even scarier than the crackling of the glacier. She wondered if she could use her power to control the weapons, maybe disarm the ghosts, but she was afraid to try. Imperial gold wasn’t just a precious metal. It was deadly to demigods and monsters. Trying to control that much at once would be like trying to control plutonium in a reactor. If she failed, she might wipe Hubbard Glacier off the map and kill her friends.

‘Thanatos!’ Hazel turned to the robed figure. ‘We’re here to rescue you. If you control these shades, tell them -’

Her voice faltered. The god’s hood fell away and his robes dropped off as he spread his wings, leaving him in only a sleeveless black tunic belted at the waist. He was the most beautiful man Hazel had ever seen.

His skin was the colour of teakwood, dark and glistening like Queen Marie’s old seance table. His eyes were as honey gold as Hazel’s. He was lean and muscular, with a regal face and black hair flowing down his shoulders. His wings glimmered in shades of blue, black and purple.

Hazel reminded herself to breathe.

Beautiful was the right word for Thanatos – not handsome, or hot, or anything like that. He was beautiful the way an angel is beautiful – timeless, perfect, remote.

‘Oh,’ she said in a small voice.

The god’s wrists were shackled in icy manacles, with chains that ran straight into the glacier floor. His feet were bare, shackled round the ankles and also chained.