Kally had seen a hellhound before. Percy kept one as a kind of pet here at camp. The giant dog was perfectly harmless to the other campers though – how could she not be with a name like Mrs O'Leary?
But this was no hellhound. It looked like Mrs O'Leary's bigger, angrier, two-headed, snake-tailed cousin.
The creature growled, causing the ground to rumble. Then it let out an ear-splitting bark. It fixed its glowing red eyes on each demigod that still stood there individually.
Almost everyone had fled the arena once the mutt had pulled itself out of that crack. Kally was sure they had run to get Chiron or Mr D or someone that could help them for gods' sake.
Now only Nico, Kally, Percy, Pollux, Annabeth and Rachel stood facing the beast. Five demigods and an Oracle against one huge demonic dog with two heads.
Perfect.
Annabeth was the first to react in any way other than frozen terror. She shook off the shock and charged the monster dog with her dagger, slashing it through the air.
Seeing Annabeth go near the thing must have snapped Percy out of his trance because he was soon right beside her, Riptide moving as though it had a nervous tick.
Pollux ran toward the thing too, sword raised high above his head. Soon everyone was hacking away at bits of the monster except for Rachel.
She just stood in the stands watching the scene unfold, an irritated and thoughtful expression on her face. Soon she scooped up some rocks from the ground and began lobbing them at the dog as hard as she could.
This just seemed to annoy the thing. It growled again and everyone lost their footing as the ground vibrated once again.
Kally didn't have time to stop swinging her sword, but as she did she took in a quick vision of the battlefield.
Annabeth had somehow managed to get nearly beneath the dog's feet and was slashing away with her knife at his paws, legs, knees; anything she could get her knife near. Nico and Pollux were trying to get a solid jab into either of beast's flanks, but to no avail.
Percy seemed to be battling the serpent tail. As Kally watched, he moved to avoid its strike and swung upwards in an attempt to behead it. Unfortunately, the snake recoiled too quickly.
That left Kally to deal with the two heads. One was preoccupied with snapping its jaws at Nico, and the other was glaring at Rachel who was still pegging rocks.
'What in the name of Zeus is this thing?' Percy shouted over the noise.
It was Annabeth who answered. 'I think it's Orthus!' she shouted back between jabs. 'He was charged with protecting the herd of red cattle belonging to Geryon!'
'So what's he doing here?' called Pollux, not taking his eyes off the dog's head that had now taken more interest in him than Nico.
'No idea!' screamed Annabeth. She dropped to her knees and rolled out of the way of Orthus's huge paw. 'Someone from the inside must have let him in! No monsters can pass through the borders of camp without someone letting them in!'
'Any idea how to kill it?' Kally yelled to Annabeth. She dared not move her eyes off the dog's heads in case one of them got tired of looking at Rachel or Pollux.
'Hercules beat him in his tenth labour,' Annabeth called in reply. 'Apparently he just hit him over the head with his club and killed him.'
'What a shame we're short of giant-dog-killing clubs.' Percy shouted.
'So what do we do?' Kally asked again, ignoring Percy's sarcastic comment.
Annabeth didn't reply. It took Percy's pained cry of 'Annabeth!' to understand why. Orthus's paw had caught her over the back of the head, knocking her out.
Percy began to run toward the unconscious blond but was knocked back by the slithering tail end of Orthus. He slumped to the ground and snapped his head up to the serpent.
He leapt up and, with a new rage, brought his sword down over the snake's head. This time, it parted from its body and rolled across the ground.
Kally had been so preoccupied watching Percy battle that she hadn't noticed Orthus's second head turn its attention away from Rachel and onto her. The creature's head snapped its jaws right next to Kally's head.
She screamed and dive rolled out of the way. 'Percy!' she cried. 'Help!'
Percy looked up from the dog's tail end. He glanced towards Annabeth, torn. Kally screamed again. Percy shook his head quickly and looked up at the grand stands. 'Rachel! Get Annabeth out of there!' Then he ran to Kally's side.
Kally was really beginning to regret not wearing a helmet. Orthus's jaws kept on snapping closed right beside her head and it was getting harder to avoid them. She was already worn out from her fight with Pollux, but dodging a giant dog head was completely fatiguing.
Percy managed to swipe the muzzle with Riptide, leaving a gash dripping red blood.
Out of the corner of her eye, Kally spotted Rachel dashing between Orthus's legs to get to Annabeth.
Together, Kally and Percy fought the dog's head. It was starting to look up for the duo when suddenly it became two-on-two. Orthus's other head spun around to face Kally, his red eyes glowing viciously.
'Can you handle one on your own?' Percy asked loudly.
Kally shook nervously. 'I don't know. I'm pretty tired.'
Percy gave her a solemn look. 'You're gonna have to try.'
Orthus snapped at her, still going for her head. Why does this thing like my head so much? she wondered.
After only moments, Kally felt exhausted. She chanced a look at the grand stands to see if Rachel had got Annabeth out yet. She felt slightly better seeing Rachel back at her spot pegging rocks again, Annabeth lying motionless beside her.
Suddenly Nico perked up. 'I have an idea!' he cried, before bolting into the forest.
Now Pollux was left taking the flanks alone while Percy helped Kally with Orthus's heads. Great, Kally thought. Now what?
'Percy, what now?'
Percy grunted a little. He was pretty caught up with Orthus's first head to reply. But he let out a long, shrill whistle. Not even a minute later Mrs O'Leary bounded through the arena gate, happily prancing toward Percy.
'Mrs O'Leary!' he called to her. 'Help us girl! Attack Orthus!'
Somehow the hellhound understood. She leapt at Orthus, even though he almost twice her size. The force and the surprise were enough to knock the monster to the ground momentarily. The crack in the ground opened up a little wider.
Kally was suddenly struck with an idea. She tried calling out to Pollux.
'Pollux!' she shouted as Mrs O'Leary was thrown off the back off Orthus and into a wall. He turned his head away slightly to look at her. 'Can you get a sword into this thing's chest? Maybe between its heads?'
'Between the heads, are you crazy?' he yelled back, ducking to dodge the limp tail that flew over his head.
'Maybe,' she replied. 'But we're running out of options! Just, try your best!'
Pollux grunted and ran to Kally's side, then began thrusting his sword towards the gap between Orthus's heads.
'No, not yet!' Kally shouted. He turned to her in exasperation. 'Just keep its head busy until I say to stab him, okay?'
He grunted again but did as she asked. This left Kally free to tell Rachel to keep the rocks coming. As she turned to talk to Percy, something hard hit her in the back of the head.
She whirled around and saw rocks the size of a mini-fridge flying over the border of the arena. Rachel looked as clueless as Kally did. She didn't know anyone who could throw rocks that size.
Then Nico ran in from the forest, another boulder rolling along behind him. He waved his arm and the boulder zipped through the air and into Orthus's right flank.
The two heads both growled and spun to face Nico. He paled slightly, which was hard for someone as pale as Nico. And then Orthus ran at him.
Nico dive rolled beneath the monster and brought his sword up us he passed the underbelly, cutting deep. Orthus yelped in surprise as Nico stood up, behind him now, and sent another boulder flying into the thing's heads.
Kally turned away, sure Nico could defend himself for just a little while. She bolted to Percy, who was about to make break for it towards Nico. She tugged at his arm.
'Percy, wait! We have to get him back into that crack somehow.' Kally told him her plan. 'Are you sure it'll work?' he asked when she was done.
'I don't know, but it's all we got,' she said. He nodded firmly.
'Let's do it.'
Percy ran to the injured Mrs O'Leary while Kally raced to help Pollux and Nico. And just in time. They were on death's doorstep by the time she reached them. She pulled them behind a huge boulder about the size of a standard kitchen.
'Nico, how many more rocks have you got?'
Nico cringed slightly. 'One.' He gestured to a stone that seemed dwarfed by the pile of rock they were hiding behind. 'I couldn't exactly find a huge amount of big rocks in the time I had.'
'Okay, well don't use it yet.' Kally ordered.
'Why not?' Nico gaped. 'We haven't got anything left to use.'
'Just trust me.' Kally begged. 'Wait for my signal.'
Nico nodded reluctantly. She made sure Pollux was still ready to stab Orthus between his heads. Then she scaled the grand stands and stood next to Rachel, getting a view over the arena.
'I hope you've got a plan genius,' Rachel said between her teeth, pegging another rock at Orthus.
'Don't worry about what I'm doing,' Kally said indignantly. 'Just get him somewhere near the crack.'
"The crack" had become more of a huge pit that didn't seem to have an end. Which probably meant that it went straight down into Tartarus. Well, she hoped anyway.
Rachel did as commanded and managed to get Orthus angry enough to come closer to her instead of checking out the boulder where Nico and Pollux still hid. She glanced at Kally. 'If you're thinking about the right time to say go, that would be now.'
'NOW!' Kally yelled as loud as she could.
Pollux ran out from behind the rock and caught the attention of the monstrous dog. He risked throwing his sword towards its heads, and was rewarded when it lodged itself between its necks.
Orthus yelped and then stumbled backwards as Nico sent his final rock flying through the air and into his gut.
A shrill whistle pierced the air, and Mrs O'Leary broke into a run at Orthus from the other side, Percy sitting proudly on her back. She collided with him mid-jump, knocking the both of them opposite directions. Orthus slumped to the ground.
The three-sided assault was working exactly as Kally had hoped. She grinned and turned to Rachel to celebrate. But Rachel looked cross.
'It didn't work!' she snapped. She gestured to the two-headed monster that was slowly rising from the ground. Mrs O'Leary's attack hadn't knocked him as far back as Kally had hoped, and instead of falling into the crevice, he had just landed beside it.
Desperately, she scanned the arena for her friends. Percy was trapped underneath an unconscious hellhound. Pollux was on his knees, trying to breathe. And Nico looked about to pass out.
'Nico!' Kally screamed. He managed to look upwards. 'Can you move the boulder? It didn't work!'
Nico barely managed to rasp out the words, 'Too… big… tired…'
It was hopeless then. They had no more tricks. Everyone who could do anything was exhausted, unconscious, or trapped under a hellhound. Kally slumped to her knees, about to give into her own fatigue.
Suddenly a sound reached her ears. She looked up and saw Chiron and what looked like half of the Apollo cabin, all armed with bows and arrows aimed directly at Orthus. They pulled back their drawstrings and let fly a volley of bronze arrows.
Orthus squealed again. He stumbled and tripped over his own feet. Unfortunately, he fell away from the pit.
Kally had to do something. She knew arrows alone wouldn't kill Orthus. He had to go back to Tartarus.
She wished that the stupid boulder below her would just take him out. She collapsed to the earth and clenched her hands in pain.
She glanced upwards at the arena and saw the boulder scrape across the ground and push Orthus to the edge of the pit.
And just as the monster fell into Tartarus, everything faded to black.
