The House of Hades (Heroes of Olympus Book 4)

guys!’ Piper called from the bow. ‘Better get over here. You need to see this.’
    They’d found the source of the dark lightning.
    The
Argo II
hovered directly over the river. A few hundred metres away at the top of the nearest hill stood a cluster of ruins. They didn’t look like much – just some crumbling walls encircling the limestone shells of a few buildings – but, from somewhere within the ruins, tendrils of black ether curled into the sky, like a smoky squid peeking from its cave. As Frank watched, a bolt of dark energy ripped through the air, rocking the ship and sending a cold shockwave across the landscape.
    ‘The Necromanteion,’ Nico said. ‘The House of Hades.’
    Frank steadied himself at the rail. He supposed it was too late to suggest turning back. He was starting to feel nostalgic about the monsters he’d fought in Rome. Heck, chasing poison cows through Venice had been more appealing than this place.
    Piper hugged her arms. ‘I feel vulnerable floating up here like this. Couldn’t we set down in the river?’
    ‘I wouldn’t,’ Hazel said. ‘That’s the River Acheron.’
    Jason squinted in the sunlight. ‘I thought the Acheron was in the Underworld.’
    ‘It is,’ Hazel said. ‘But its headwaters are in the mortal world. That river below us? Eventually it flows underground, straight into the realm of Pluto – er, Hades. Landing a demigod ship on those waters –’
    ‘Yeah, let’s stay up here,’ Leo decided. ‘I don’t want any zombie water on my hull.’
    Half a kilometre downstream, some fishing boats were puttering along. Frank guessed they didn’t know or care about the history of this river. Must be nice, being a regular mortal.
    Next to Frank, Nico di Angelo raised the sceptre of Diocletian. Its orb glowed with purple light, as if in sympathy with the dark storm. Roman relic or not, the sceptre troubled Frank. If it really had the power to summon a legion of the dead … well, Frank wasn’t sure that was such a great idea.
    Jason had once told him that the children of Mars had a similar ability. Supposedly, Frank could call on ghostly soldiers from the losing side of any war to serve him. He’d never had much luck with that power, probably because it freaked him out too much. He was worried he might
become
one of those ghosts if they lost this war – eternally doomed to pay for his failures, assuming there was anyone left to summon him.
    ‘So, uh, Nico …’ Frank gestured at the sceptre. ‘Have you learned to use that thing?’
    ‘We’ll find out.’ Nico stared at the tendrils of darkness undulating from the ruins. ‘I don’t intend to try until I have to. The Doors of Death are already working overtime bringing in Gaia’s monsters. Any more activity raising the dead and the Doors might shatter permanently, leaving a rip in the mortal world that can’t be closed.’
    Coach Hedge grunted. ‘I hate rips in the world. Let’s go bust some monster heads.’
    Frank looked at the satyr’s grim expression. Suddenly he had an idea. ‘Coach, you should stay on board, cover us with the ballistae.’
    Hedge frowned. ‘Stay behind? Me? I’m your best soldier!’
    ‘We might need air support,’ Frank said. ‘Like we did in Rome. You saved our
braccae
.’
    He didn’t add:
Plus, I’d like you to get back to your wife and baby alive.
    Hedge apparently got the message. His scowl relaxed. Relief showed in his eyes.
    ‘Well …’ he grumbled, ‘I suppose somebody’s got to save your
braccae
.’
    Jason clapped the coach on the shoulder. Then he gave Frank an appreciative nod. ‘So that’s settled. Everybody else – let’s get to the ruins. Time to crash Gaia’s party.’

LXVI
     

FRANK
     
    D ESPITE THE MIDDAY HEAT and the raging storm of death energy, a group of tourists was climbing over the ruins. Fortunately there weren’t many and they didn’t give the demigods a second look.
    After the crowds in Rome, Frank had stopped worrying too much about getting noticed. If they could fly their warship into the Roman Colosseum with ballistae blazing and not even cause a traffic slowdown, he figured they could get away with anything.
    Nico led the way. At the top of the hill, they climbed over an old retaining wall and down into an excavated trench. Finally they arrived at a stone doorway leading straight into the side of the hill. The death storm seemed to originate right above their heads. Looking up at the swirling tentacles of darkness,