One train and two smelly buses on Percy's card later he, Thalia and Annabeth set foot on Death Valley National Park sand. Though three would enter, only two of them would leave. There was a sense of dread hanging in the air as Thalia scanned the boards for a tour of the area they were looking for. After half an hour of flipping through tour booklets Annabeth stumbled on a trek to a place called Hatred Mountain, which, according to Shoshone lore was the place where evil spirits went to die.
Percy walked up to the ticket desk to buy their tour passes, and called the other two into the waiting room. An hour later who should walk through the door, but good ole Hermes. He had a tacky getup comprised of a goofy ranger out, flare gun, "walking stick" (Caduceus), and a belt with about half a dozen full sized Nalgene water bottles clipped to it. As he turned toward the room he called out,
"Jackson, party of three?" When his eyes locked onto Percy they lit up like a Christmas tree. "Jackson party, please come with me," motioning for the kids to follow him. After they were in the pre trek room Hermes turned and looked directly at the kids. "You guys now that there is a dragon out their right? That's why I lead this trek; it leaves mortals well enough alone when it smells a god, but three demigods, two of which are children of the big three, will be completely irresistible to that monster. It has been ruing the day it was first slain 4 thousand years ago, and any would be hero will be a light snack compared to its normal prey of mountain cyclopi.
"But," began Thalia, indignantly, "That's why we're here. I was given a quest to kill that thing. If it weren't important I wouldn't have gotten the quest for it."
"I've killed way worse, and who says I'm not just as good as whoever killed this thing last time?" said Percy, crossing his arms and standing next to Thalia. She, however wished he hadn't stood up for her; it made it that much harder to deny her feelings, and damn she was beginning to love the smell of the beach.
"Percy and I survived Tartarus, we can face some stupid dragon, right Percy" added Annabeth, looking to Percy who nodded in agreement. Hermes sighed and opened the door to the trailhead.
Several hours later, the sky was dark, and they had finally reached the butte known as Hatred Mountain. About 3 miles away Hermes said he would go no further, claiming he would not lead heroes to their death, and if they wanted to turn back it would be no shame, but even one step further and he would not be responsible if any of them died.
When none of them chose to turn back Hermes sighed, "So be it," and was gone. They walked the last few miles in silence. When they were about half a mile from the butte, they heard a roar that could curdle golden ichor. An absolutely massive black shape darted from a cave in the side of the rock and dove to meet them. The demigods rushed back as it slammed into the sand creating a shockwave of quartz and feldspar. It reared its dark scaly head and shot a plume of green fire from its mouth and charged Thalia, and thanks to the gift Percy had gotten her, she narrowly avoided having to go home with her guts in a bag. Riptide seemed to be ineffective at cleaving its scales, though it surprised all of the demigods when a shard of scale broke off and landed in the sand a few yards away. This enraged the beast, causing it to take its eyes off of Thalia. It sniffed Percy before uttering the words, "O gios tou theoú tis thálassas, adelfós tou kynigoú: orycheío foniás, thánatos gia sas, sýntoma gi 'aftón, tóte o patéras sas kai óloi oi álloi Olýmpioi." which Percy didn't entirely understand, but he heard the word thanatos, which he knew meant death, which was never good.
"No way," gasped Annabeth, "Orion killed this thing?"
"What!?" shouted Thalia as she launched a hefty lightning bolt at the monster.
Annabeth gave a rough translation of what that dragon had said. Its words led her to believe Orion was the one who killed it so long ago. She told Percy only he could kill it, unless of course he had a half-brother of his laying around somewhere, but the dragon just chuckled and dove at Percy, who took a nice chunk out of cheek with Riptide.
The dragon only got angrier and angrier as Percy continued to evade him. However, when a lucky shot from Thalia's bow hit the dragon in the eye it turned to her and tossed her against a rock. Percy ran to her and the dragon snapped at him, but was greeted only with another jab in his eye, this time from Annabeth who was latched onto his face. He knocked her off only to receive yet more arrows and cuts. Percy was beginning to wish he had kept his curse of Achilles, at least then he wouldn't have to worry about those massive fucking teeth.
The monster gave out another mighty roar. Its endgame was now beginning. It had to die now, or it would be them who would die. Somehow it seemed faster, stronger, and even more bloodthirsty. It launched itself into the air, flew higher and higher until it began to descend. Aimed directly at Percy, it looked like his old buddy death was about to come for him. It was close enough for Percy to feel its breath when he was shoved from behind. He looked back and saw Annabeth mouth, 'I love you, goodbye…' before the dragon clamped down, consuming Annabeth and a section of his leg.
As Percy sat, bleeding in the sand, the dragon gulped down the contents of its mouth. Percy threw riptide as hard as he could, causing it to lodge between the dragon's eyes. Thalia rushed forward to pull Percy away, but, with tears streaming down his face, he shouted out, causing an orb of blue magic to collect near his hand. Thalia felt what little moisture was in the dry up as it was added to the ball. Before long the magic was the size of a basketball, and launched at the dragon hitting it square in the head.
It seemed to shake off the attack. However cracks appeared on riptide, bright and glowing like the eyes of a god. Then came the boom. Riptide exploded powdering the dragon and leaving a crater in the desert. The last thing Percy saw before the pressure of the blast forced him into unconsciousness were the faces of Hermes, Thalia, and his father.