The House of Hades (Heroes of Olympus Book 4)

asked.
    Okay … if Frank was seeing a ghost that the Underworld kids couldn’t see, something was definitely wrong. He felt like the floor was vibrating underneath him. Then he realized it
was
vibrating.
    ‘We need to get to that exit,’ he said. ‘Now!’
    Hazel almost had to tackle him to restrain him. ‘Wait, Frank! This floor is
not
stable, and underneath … well, I’m not sure
what’s
underneath. I need to scout a safe path.’
    ‘Hurry, then,’ he urged.
    He drew his bow and herded Hazel along as fast as he dared. Leo scrambled behind him to provide light. The others guarded the rear. Frank could tell he was scaring his friends, but he couldn’t help it. He knew in his gut they had only seconds before …
    In front of them, the legionnaire ghost vaporized. The cavern reverberated with monstrous roars – dozens, maybe hundreds of enemies coming from every direction. Frank recognized the throaty bellow of the Earthborn, the screech of gryphons, the guttural war cries of Cyclopes – all soundshe remembered from the Battle of New Rome, amplified underground, echoing in his head even louder than the war god’s voices.
    ‘Hazel, don’t stop!’ Nico ordered. He pulled the sceptre of Diocletian from his belt. Piper and Jason drew their swords as the monsters spilled into the cavern.
    A vanguard of six-armed Earthborn threw a volley of stones that shattered the bone-and-jewel floor like ice. A fissure spread across the centre of the room, coming straight towards Leo and Hazel.
    No time for caution. Frank tackled his friends, and the three of them skidded across the cavern, landing at the edge of the ghost’s tunnel as rocks and spears flew overhead.
    ‘Go!’ Frank yelled. ‘Go, go!’
    Hazel and Leo scrambled into the tunnel, which seemed to be the only one free of monsters. Frank wasn’t sure that was a good sign.
    Two metres in, Leo turned. ‘The others!’
    The entire cavern shuddered. Frank looked back and his courage crumbled to dust. Dividing the cavern was a new fifteen-metre-wide chasm, spanned only by two rickety stretches of bone flooring. The bulk of the monster army was on the opposite side, howling in frustration and throwing whatever they could find, including each other. Some attempted to cross the bridges, which creaked and crackled under their weight.
    Jason, Piper and Nico stood on the near side of the chasm, which was good, but they were surrounded by a ring ofCyclopes and hellhounds. More monsters kept pouring in from the side corridors, while gryphons wheeled overhead, undeterred by the crumbling floor.
    The three demigods would never make it to the tunnel. Even if Jason tried to fly them, they’d be shot out of the air.
    Frank remembered the voice of his ancestor:
At the break, you must take charge.
    ‘We have to help them,’ Hazel said.
    Frank’s mind raced, doing battle calculations. He saw exactly what would happen – where and when his friends would be overwhelmed, how all six of them would die here in this cavern … unless Frank changed the equation.
    ‘Nico!’ he yelled. ‘The sceptre.’
    Nico raised Diocletian’s sceptre, and the cavern air shimmered purple. Ghosts climbed from the fissure and seeped from the walls – an entire Roman legion in full battle gear. They began taking on physical form, like walking corpses, but they seemed confused. Jason yelled in Latin, ordering them to form ranks and attack. The undead just shuffled among the monsters, causing momentary confusion, but that wouldn’t last.
    Frank turned to Hazel and Leo. ‘You two keep going.’
    Hazel’s eyes widened. ‘What? No!’
    ‘You have to.’ It was the hardest thing Frank had ever done, but he knew it was the only choice. ‘Find the Doors. Save Annabeth and Percy.’
    ‘But –’ Leo glanced over Frank’s shoulder. ‘Hit the deck!’
    Frank dived for cover as a volley of rocks slammed overhead. When he managed to get up, coughing and covered indust, the entrance to the tunnel was gone. An entire section of wall had collapsed, leaving a slope of smoking rubble.
    ‘Hazel …’ Frank’s voice broke. He had to hope she and Leo were alive on the other side. He couldn’t afford to think otherwise.
    Anger swelled in his chest. He turned and charged towards the monster army.

LXVII
     

FRANK
     
    F RANK WAS NO EXPERT ON GHOSTS, but the dead legionnaires must have all been demigods, because they were totally ADHD.
    They clawed their way out of the pit, then milled