Of course not, Frank thought. He's Greek.

Jason and Piper stood at Nico's back. Jason summoned gusts of wind to blast aside javelins and arrows. He deflected a vial of Greek fire right up the throat of a gryphon, which burst into flames and spiralled into the pit. Piper put her new sword to good use, while spraying food from the cornucopia in her other hand using hams, chickens, apples and oranges as interceptor missiles. The air above the chasm turned into a fireworks show of flaming projectiles, exploding rocks and fresh produce.

Still, Frank's friends couldn't hold out forever. Jason's face was already beaded with sweat. He kept shouting in Latin: 'Form ranks!' But the dead legionnaires wouldn't listen to him, either. Some of the zombies were helpful just by standing in the way, blocking monsters and taking fire. If they kept getting mowed down, though, there wouldn't be enough of them left to organize.

'Make way!' Frank shouted. To his surprise, the dead legionnaires parted for him. The closest ones turned and stared at him with blank eyes, as if waiting for further orders.

'Oh, great ...' Frank mumbled.

In Venice, Mars had warned him that his true test of leader-ship was coming. Frank's ghostly ancestor had urged him to take charge. But, if these dead Romans wouldn't listen to Jason, why should they listen to him? Because he was a child of Mars, or maybe because ...

The truth hit him. Jason wasn't quite Roman any more. His time at Camp Half-Blood had changed him. Reyna had recognized that. Apparently, so did the undead legionnaires. If Jason no longer gave off the right sort of vibe or aura of a Roman leader ...

Frank made it to his friends as a wave of Cyclopes crashed into them. He lifted his sword to parry a Cyclops's club, then stabbed the monster in the leg, sending him backwards into the pit. Another one charged. Frank managed to impale him, but blood loss was making him weak. His vision blurred. His ears rang.

He was dimly aware of Jason on his left flank, deflecting the incoming missiles with wind; Piper on his right, yelling charmspeak commands encouraging the monsters to attack each other or take a refreshing jump into the chasm.

'It'll be fun!' she promised.

A few listened, but across the pit the empousai were counter-ing her orders. Apparently they had charmspeak too. The monsters crowded so thickly around Frank that he could barely use his sword. The stench of their breath and body odour was almost enough to knock him out, even without the arrow throbbing in his arm.

What was Frank supposed to do? He'd had a plan, but his thoughts were getting fuzzy.

'Stupid ghosts!' Nico shouted.

'They won't listen!' Jason agreed.

That was it. Frank had to make the ghosts listen.

He summoned all his strength and yelled, 'Cohorts lock shields!'

The zombies around him stirred. They lined up in front of Frank, putting their shields together in a ragged defensive formation. But they were moving too slowly, like sleepwalkers, and only a few had responded to his voice.

'Frank, how did you do that?' Jason yelled.

Frank's head swam with pain. He forced himself not to pa.s.s out. 'I'm the ranking Roman officer,' he said. 'They uh, they don't recognize you. Sorry.'

Jason grimaced, but he didn't look particularly surprised. 'How can we help?'

Frank wished he had an answer. A gryphon soared overhead, almost decapitating him with its talons. Nico smacked it with the sceptre of Diocletian, and the monster veered into a wall.

'Orbem formate!' Frank ordered.

About two dozen zombies obeyed, struggling to form a defensive ring around Frank and his friends. It was enough to give the demiG.o.ds a little respite, but there were too many enemies pressing forward. Most of the ghostly legionnaires were still wandering around in a daze.

'My rank,' Frank realized.

'All these monsters are rank!' Piper yelled, stabbing a wild centaur.

'No,' Frank said. 'I'm only a centurion.'

Jason cursed in Latin. 'He means he can't control a whole legion. He's not of high enough rank.'

Nico swung his black sword at another gryphon. 'Well, then, promote him!'

Frank's mind was sluggish. He didn't understand what Nico was saying. Promote him? How?

Jason shouted in his best drill-sergeant voice: 'Frank Zhang! I, Jason Grace, praetor of the Twelfth Legion Fulminata, give you my final order: I resign my post and give you emergency field promotion to praetor, with the full powers of that rank. Take command of this legion!'

Frank felt as if a door had opened somewhere in the House of Hades, letting in a blast of fresh air that swept through the tunnels. The arrow in his arm suddenly didn't matter. His thoughts cleared. His eyesight sharpened. The voices of Mars and Ares spoke in his mind, strong and unified: Break them!

Frank hardly recognized his own voice when he yelled: 'Legion, agmen formate!'

Instantly, every dead legionnaire in the cavern drew his sword and raised his shield. They scrambled towards Frank's position, pushing and hacking monsters out of their way until they stood shoulder to shoulder with the comrades, arranging themselves in a square formation. Stones, javelins and fire rained down, but now Frank had a disciplined defensive line sheltering them behind a wall of bronze and leather.

'Archers!' Frank yelled. 'Eiaculare flammas!'

He didn't hold out much hope the command would work. The zombies' bows couldn't be in good shape. But, to his surprise, several dozen ghostly skirmishers nocked arrows in unison. Their arrowheads caught fire spontaneously and a flaming wave of death arced over the legion's line, straight into the enemy. Cyclopes fell. Centaurs stumbled. A telkhine shrieked and ran in circles with a burning arrow impaled in his forehead.

Frank heard a laugh behind him. He glanced back and couldn't believe what he saw. Nico di Angelo was actually smiling.

'That's more like it,' Nico said. 'Let's turn this tide!'

'Cuneum formate!' Frank yelled. 'Advance with pila!'

The zombie line thickened in the centre, forming a wedge designed to break through the enemy host. They lowered their spears in a bristling row and pushed forward.

Earthborn wailed and threw boulders. Cyclopes smashed their fists and clubs against the locked shields, but the zombie legionnaires were no longer paper targets. They had inhuman strength, hardly wavering under the fiercest attacks. Soon the floor was covered with monster dust. The line of javelins chewed through the enemy like a set of giant teeth, felling ogres and snake women and h.e.l.lhounds. Frank's archers shot gryphons out of the air and caused chaos in the main body of the monster army across the chasm.

Frank's forces began to take control of their side of the cavern. One of the stone bridges collapsed, but more monsters kept pouring over the other one. Frank would have to stop that.

'Jason,' he called, 'can you fly a few legionnaires across the pit? The enemy's left flank is weak see? Take it!'

Jason smiled. 'With pleasure.'

Three dead Romans rose into the air and flew across the chasm. Then three more joined them. Finally Jason flew himself across and his squad began cutting through some very surprised-looking telkhines, spreading fear through the enemy's ranks.

'Nico,' Frank said, 'keep trying to raise the dead. We need more numbers.'

'On it.' Nico lifted the sceptre of Diocletian, which glowed even darker purple. More ghostly Romans seeped from the walls to join the fight.

Across the chasm, empousai shouted commands in a language Frank didn't know, but the gist was obvious. They were trying to sh.o.r.e up their allies and keep them charging across the bridge.

'Piper!' Frank yelled. 'Counter those empousai! We need some chaos.'

'Thought you'd never ask.' She started catcalling at the female demons: 'Your makeup is smeared! Your friend called you ugly! That one is making a face behind your back!' Soon the vampire ladies were too busy fighting one another to shout any commands.

The legionnaires moved forward, keeping up the pressure. They had to take the bridge before Jason got overwhelmed.

'Time to lead from the front,' Frank decided. He raised his borrowed sword and called for a charge.

LXVIII.

FRANK.

FRANK DIDN'T NOTICE THAT HE WAS GLOWING. Later Jason told him that the blessing of Mars had shrouded him in red light, like it had in Venice. Javelins couldn't touch him. Rocks somehow got deflected. Even with an arrow sticking out of his left biceps, Frank had never felt so full of energy.

The first Cyclops he met went down so quickly it was almost a joke. Frank sliced him in half from shoulder to waist. The big guy exploded into dust. The next Cyclops backed up nervously, so Frank cut his legs out from under him and sent him into the pit.

The remaining monsters on their side of the chasm tried to retreat, but the legion cut them down.

'Testudo formation!' Frank shouted. 'Single file, advance!'

Frank was the first one across the bridge. The dead followed, their shields locked on either side and over their heads, deflecting all attacks. As the last of the zombies crossed, the stone bridge crumbled into the darkness, but by then it didn't matter.

Nico kept summoning more legionnaires to join the fight. Over the history of the empire, thousands of Romans had served and died in Greece. Now they were back, answering the call of Diocletian's sceptre.

Frank waded forward, destroying everything in his path.

'I will burn you!' a telkhine squeaked, desperately waving a vial of Greek fire. 'I have fire!'

Frank took him down. As the vial dropped towards the ground, Frank kicked it over the cliff before it could explode.

An empousa raked her claws across Frank's chest, but Frank felt nothing. He sliced the demon into dust and kept moving. Pain was unimportant. Failure was unthinkable.

He was a leader of the legion now, doing what he was born to do fighting the enemies of Rome, upholding its legacy, protecting the lives of his friends and comrades. He was Praetor Frank Zhang.

His forces swept the enemy away, breaking their every attempt to regroup. Jason and Piper fought at his side, yelling defiantly. Nico waded through the last group of Earthborn, slashing them into mounds of wet clay with his black Stygian sword.

Before Frank knew it, the battle was over. Piper chopped through the last empousa, who vaporized with an anguished wail.

'Frank,' Jason said, 'you're on fire.'

He looked down. A few drops of oil must have splattered on his trousers, because they were starting to smoulder. Frank batted at them until they stopped smoking, but he wasn't particularly worried. Thanks to Leo, he no longer had to fear fire.

Nico cleared his throat. 'Uh ... you also have an arrow sticking through your arm.'

'I know.' Frank snapped off the point of the arrow and pulled out the shaft by the tail. He felt only a warm tugging sensation. 'I'll be fine.'

Piper made him eat a piece of ambrosia. As she bandaged his wound, she said, 'Frank, you were amazing. Completely terrifying, but amazing.'

Frank had trouble processing her words. Terrifying couldn't apply to him. He was just Frank.

His adrenalin drained away. He looked around him, wondering where all the enemies had gone. The only monsters left were his own undead Romans, standing in a stupor with their weapons lowered.

Nico held up his sceptre, its...o...b..dark and dormant. 'The dead won't stay much longer, now that the battle is over.'

Frank faced his troops. 'Legion!'

The zombie soldiers snapped to attention.

'You fought well,' Frank told them. 'Now you may rest. Dismissed.'

They crumbled into piles of bones, armour, shields and weapons. Then even those disintegrated.

Frank felt as if he might crumble too. Despite the ambrosia, his wounded arm began to throb. His eyes were heavy with exhaustion. The blessing of Mars faded, leaving him depleted. But his work wasn't done yet.

'Hazel and Leo,' he said. 'We need to find them.'

His friends peered across the chasm. At the other end of the cavern, the tunnel Hazel and Leo had entered was buried under tons of rubble.

'We can't go that way,' Nico said. 'Maybe ...'

Suddenly he staggered. He would have fallen if Jason hadn't caught him.

'Nico!' Piper said. 'What is it?'

'The Doors,' Nico said. 'Something's happening. Percy and Annabeth ... we need to go now.'

'But how?' Jason said. 'That tunnel is gone.'

Frank clenched his jaw. He hadn't come this far to stand around helplessly while his friends were in trouble. 'It won't be fun,' he said, 'but there's another way.'

LXIX.

ANNABETH.