Annabeth blushed. ‘Shut up, Silena. Hand me your dagger.’

I was afraid Annabeth was going to stab me with it. Instead she used it as a screwdriver to open a panel in the dragon’s neck. ‘Here goes nothing,’ she said.

And she started to splice together the celestial bronze wires.

It took a long time. Too long.

I figured capture the flag had to be over by now. I wondered how soon the other campers would realize we were missing and come looking for us. If Annabeth’s calculations were correct (and they always were), Beckendorf probably had five or ten minutes left before the ants got him.

Finally Annabeth stood up and exhaled. Her hands were scraped and muddy. Her fingernails were wrecked. She had a brown streak across her forehead where the dragon had decided to spit grease at her.

‘All right,’ she said. ‘It’s done, I think…’

‘You think?’ Silena asked.

‘It has to be done,’ I said. ‘We’re out of time. How do you, uh, start it? Is there an ignition switch or something?’

Annabeth pointed to its ruby eyes. ‘Those turn clockwise. I’m guessing we rotate them.’

‘If somebody twisted my eyeballs, I’d wake up,’ I agreed. ‘What if it goes crazy on us?’

‘Then… we’re dead,’ Annabeth said.

‘Great,’ I said. ‘I’m psyched.’

Together we turned the ruby eyes of the dragon. Immediately they began to glow. Annabeth and I backed up so fast we fell over each other. The dragon’s mouth opened, as if it were testing its jaw. The head turned and looked at us. Steam poured from its ears and it tried to rise.

When it found it couldn’t move, the dragon seemed confused. It cocked its head and regarded the dirt. Finally, it realized it was buried. The neck strained once, twice… and the centre of the crater erupted.

The dragon pulled itself awkwardly out of the ground, shaking clumps of mud from its body the way a dog might, splattering us from head to toe. The automaton was so awesome, none of us could speak. I mean, sure it needed a trip through the car wash, and there were a few loose wires sticking out here and there, but the dragon’s body was amazing – like a high-tech tank with legs. Its sides were plated with bronze and gold scales, encrusted with gemstones. Its legs were the size of tree trunks and its feet had steel talons. It had no wings – most Greek dragons don’t – but its tail was at least as long as its main body, which was the size of a school bus. The neck creaked and popped as it turned its head to the sky and blew a column of triumphant fire.

‘Well…’ I said in a small voice. ‘It still works.’

Unfortunately, it heard me. Those ruby eyes zeroed in on me, and it stuck its snout five centimetres from my face. Instinctively, I reached for my sword.

‘Dragon, stop!’ Silena yelled. I was amazed her voice still worked. She spoke with such command that the automaton turned its attention to her.

Silena swallowed nervously. ‘We’ve woken you to defend the camp. You remember? That is your job!’

The dragon tilted its head as if it were thinking. I figured Silena had about a fifty-fifty chance of getting blasted with fire. I was considering jumping on the thing’s neck to distract it when Silena said, ‘Charles Beckendorf, a son of Hephaestus, is in trouble. The Myrmekes have taken him. He needs your help.’

At the word Hephaestus the dragon’s neck straightened. A shiver rippled through its metal body, throwing a new shower of mud clods all over us.

The dragon looked around as if trying to find an enemy.

‘We have to show it,’ Annabeth said. ‘Come on, dragon! This way to the son of Hephaestus! Follow us!’

Just like that, she drew her sword, and the three of us climbed out of the pit.

‘For Hephaestus!’ Annabeth yelled, which was a nice touch. We charged through the woods. When I looked behind us, the bronze dragon was right on our tail, its red eyes glowing and steam coming out its nostrils.

It was a good incentive to keep running fast as we headed for the Ant Hill.

When we got to the clearing, the dragon seemed to catch Beckendorf’s scent. It barrelled ahead of us, and we had to jump out of its way to avoid getting flattened. It crashed through the trees, joints creaking, feet pounding craters into the ground.

It charged straight for the Ant Hill. At first, the Myrmekes didn’t know what was happening. The dragon stepped on a few of them, smashing them to bug juice. Then their telepathic network seemed to light up, like: Big dragon. Bad!

All the ants in the clearing turned simultaneously and swarmed over the dragon. More ants poured out of the hill – hundreds of them. The dragon blew fire and sent a whole column of them into a panicked retreat. Who knew ants were flammable? But more kept coming.

‘Inside, now!’ Annabeth told us. ‘While they’re focused on the dragon!’

Silena led the charge; it was the first time I’d ever followed a child of Aphrodite into battle. We ran past the ants, but they ignored us. For some reason they seemed to consider the dragon a bigger threat. Go figure.

We plunged into the nearest tunnel and I almost gagged from the stench. Nothing, I mean nothing, stinks worse than a giant ant lair. I could tell they let their food rot before eating it. Somebody seriously needed to teach them about refrigerators.

Our journey inside was a blur of dark tunnels and mouldy rooms carpeted with old ant shells and pools of goo. Ants surged past us on their way to battle, but we just stepped aside and let them pass. The faint bronze glow of my sword gave us light as we made our way deeper into the nest.

‘Look!’ Annabeth said.

I glanced into a side room, and my heart skipped a beat. Hanging from the ceiling were huge, gooey sacks – ant larvae, I guess – but that’s not what got my attention. The cave floor was heaped with gold coins, gems and other treasures – helmets, swords, musical instruments, jewellery. They glowed the way magic items do.

‘That’s just one room,’ Annabeth said. ‘There are probably hundreds of nurseries down here, decorated with treasure.’

‘It’s not important,’ Silena insisted. ‘We have to find Charlie!’

Another first: a child of Aphrodite uninterested in jewellery.

We forged on. After six more metres, we entered a cavern that smelled so bad my nose shut down completely. The remains of old meals were piled as high as sand dunes – bones, chunks of rancid meat, even old camp meals. I guess the ants had been raiding the camp’s compost heap and stealing our leftovers. At the base of one of the heaps, struggling to pull himself upright, was Beckendorf. He looked awful, partly because his camouflage armour was now the colour of garbage.

‘Charlie!’ Silena ran to him and tried to help him up.

‘Thank the gods,’ he said. ‘My – my legs are paralysed!’

‘It’ll wear off,’ Annabeth said. ‘But we have to get you out of here. Percy, take his other side.’

Silena and I hoisted Beckendorf up, and the four of us started back through the tunnels. I could hear distant sounds of battle – metal creaking, fire roaring, hundreds of ants snapping and spitting.

‘What’s going on out there?’ Beckendorf asked. His body tensed. ‘The dragon! You didn’t – reactivate it?’

‘Afraid so,’ I said. ‘Seemed like the only way.’

‘But you can’t just turn on an automaton! You have to calibrate the motor, run a diagnostic… There’s no telling what it’ll do! We’ve got to get out there!’

As it turned out, we didn’t need to go anywhere, because the dragon came to us. We were trying to remember which tunnel led to the exit when the entire hill exploded, showering us in dirt. Suddenly we were staring at open sky. The dragon was right above us, thrashing back and forth, smashing the Ant Hill to bits as it tried to shake off the Myrmekes crawling all over its body.

‘Come on!’ I yelled. We dug ourselves out of the dirt and stumbled down the side of the hill, dragging Beckendorf with us.

Our friend the dragon was in trouble. The Myrmekes were biting at the joints of its armour, spitting acid all over it. The dragon stomped and snapped and blew flames, but it couldn’t last much longer. Steam was rising from its bronze skin.

Even worse, a few of the ants turned towards us. I guess they didn’t like us stealing their dinner. I slashed at one and lopped off its head. Annabeth stabbed another right between the feelers. As the celestial bronze blade pierced its shell, the whole ant disintegrated.

‘I – I think I can walk now,’ Beckendorf said, and immediately fell on his face when we let go of him.

‘Charlie!’ Silena helped him up and pulled him along while Annabeth and I cleared a path through the ants. Somehow we managed to reach the edge of the clearing without getting bitten or splashed, though one of my sneakers was smoking from acid.

Back in the clearing, the dragon stumbled. A great cloud of acid mist was roiling off its hide.

‘We can’t let it die!’ Silena said.

‘It’s too dangerous,’ Beckendorf said sadly. ‘Its wiring –’

‘Charlie,’ Silena pleaded, ‘it saved your life! Please, for me.’

Beckendorf hesitated. His face was still bright red from the ant spit, and he looked as if he were going to faint any minute, but he struggled to his feet. ‘Get ready to run,’ he told us. Then he gazed across the clearing and shouted, ‘DRAGON! Emergency defence, beta-ACTIVATE!’

The dragon turned towards the sound of his voice. It stopped struggling against the ants, and its eyes glowed. The air smelled of ozone, like before a thunderstorm.

ZZZZZAAAAAPPP!

Arcs of blue electricity shot from the dragon’s skin, rippling up and down its body and connecting with the ants. Some of the ants exploded. Others smoked and blackened, their legs twitching. In a few seconds there were no more ants on the dragon. The ones that were still alive were in full retreat, scuttling back towards their ruined hill as fingers of electricity zapped them in the butt to prod them along.

The dragon bellowed in triumph, then it turned its glowing eyes towards us.

‘Now,’ Beckendorf said, ‘we run.’

This time we did not yell, ‘For Hephaestus!’ We yelled, ‘Heeeeelp!’

The dragon pounded after us, spewing fire and zapping lightning bolts over our heads like it was having a great time.

‘How do you stop it?’ Annabeth yelled.

Beckendorf, whose legs were now working fine (nothing like being chased by a huge monster to get your body back in order) shook his head and gasped for breath. ‘You shouldn’t have turned it on! It’s unstable! After a few years, automatons go wild!’

‘Good to know,’ I yelled. ‘But how do you turn it off?’

Beckendorf looked around wildly. ‘There!’

Up ahead was an outcrop of rock, almost as tall as the trees. The woods were full of weird rock formations, but I’d never seen this one before. It was shaped like a giant skateboard ramp, slanted on one side, with a sheer drop on the other.

‘You guys, run around to the base of the cliff,’ Beckendorf said. ‘Distract the dragon. Keep it occupied!’