First Percy running off.
Then Annabeth being captured or killed.
Then the Hunters turning up.
As you can see, Thalia's day was going badly enough without an overexcited sun god (who was probably as high as his chariot) forcing her to drive the literal sun.
But first, backtrack a bit.
The Hunters had stopped ruining Thalia's day even more (by trying to talk to her.) She was left alone to overhear Bianca and Nico's conversation that she probably shouldn't have been listening to.
Nico didn't seem happy. Something about Bianca leaving him, but he eventually gave in, hugged her, and said goodbye. She replied by telling him that she wasn't going yet.
Thalia was confused at first. Then Percy appeared out of nowhere and said, "Bianca joined the Hunters."
Thalia punched a tree.
"Save hitting trees for Minecraft," Percy told her. "I don't like it either, but she's already made the oath."
Thalia started to say a curse word.
"And they're coming back to Camp Half-Blood with us," Percy interrupted.
Thalia stared at him in angry silence.
Then she finished her curse word. "I bet it was Zoë's fault! That stuck-up, no good-"
Artemis came up next to them, ignoring Thalia's glare. "He will be coming soon. He is soooo lazy in the winter."
"Who?" Thalia asked.
"Apollo," Artemis answered gravely, looking pained at how she was subjecting them to whatever was about to happen. "He is your ride to camp. But don't look, not until he parks."
Grover looked confused. "Until he-"
And then the world exploded.
At least, that was what it looked like. What actually happened was that the sun landed in front of them.
...Come to think of it, that wasn't much better.
The assorted Hunters and campers looked away. Thalia felt like her coat was melting off of her in the sudden blast of heat.
And then the light died, and it was mostly cold again.
Thalia risked a look and sucked in her breath. A red convertible Maserati Spyder had appeared out of nowhere, glowing with heat. The snow had melted and there was green grass in a perfect circle around the car. It made Thalia's shoes wet, which wasn't much help with the cold, but oh well.
The driver got out, smiling confidently. He looked about seventeen or eighteen, and his sandy golden hair hung almost into his eyes. He brushed it away, looking slightly annoyed with it, but still keeping the smile. He carried himself with confidence, or maybe just someone with a massive ego.
"Whoa," Thalia breathed. "Apollo is hot."
"He's the sun god," Percy agreed.
"That's not what I meant."
"Little sister!" Apollo beamed, turning right away to Artemis. "What's up? You never write, or call, or whatever the people do these days! I was getting worried."
Artemis sighed. "I'm fine. And I am not your little sister. We're twins, how many millennia do we have to argue-"
"SO WHAT'S UP?" Apollo interrupted. "Got the girls with you, I see. Y'all need tips on archery?" He mimed shooting a bow and made a whoosh noise as he let the invisible arrow fly.
Artemis looked like any person would look when their brother headed into their room and thought he was hilarious but was actually just an idiot. "I need a favor," she said, in a tone that suggested she would do anything to NOT have to ask for this favor. "I have some hunting to do. I need you to take my companions to Camp Half-Blood."
"Sure! Wait-" he raised his hands in a stop everything gesture. "I feel a haiku coming on."
The Hunters groaned. For once, Thalia felt sorry for them.
Apollo held up a hand dramatically, which he was the god of theater so that made sense.
"Green grass breaks through snow
Artemis pleads for my help
I am so cool."
Okay, yeah, definitely a big ego.
Apollo vs Smallishbeans, who would win?
"If this is poetry worthy of the gods, their standards aren't as high as I thought," Percy muttered. Thalia held back a snort.
"Simply incredible," Artemis drawled sarcastically. "The last line is only four syllables."
Apollo frowned. "Is it?"
"Yes," Artemis said. "Try I am so big-headed."
Apollo considered that. "No," he said. "Because that's six syllables."
He continued to think.
Zoë came up next to them. "Ever since he visited Japan, he couldn't stop speaking in haiku... It isn't as bad as when he visited Limerick, though. If I hear one more poem beginning with there once was a goddess from Sparta-" she shuddered.
Thalia ignored her, preferring to look at the hot, but not very bright (oh, the irony) sun god instead.
"I've got it!" Apollo said. "I am so awesome." He bowed, looking incredibly pleased with himself. "Okay, right. Transportation to Camp Half-Blood!"
"These demigods need it as well," Artemis said, gesturing to Percy, Thalia, Nico, and Grover. "And satyr."
Apollo surveyed them.
Thalia felt her face get hot as he looked at her. "Hi, Lord Apollo."
Percy was trying to hold in laughter. Thalia smacked him.
"Right!" Apollo said, flashing a smile. "We're gonna need some more seating, then."
His flashy car suddenly disappeared and was replaced by an equally flashy school bus.
"Alright!" Apollo said excitedly. "Who's gonna drive?"
"Whoa! It can turn into a bus?" Nico gasped. "Can I drive?"
"No," Apollo said. "Too young. Hmm..."
"Me!" Grover volunteered.
"Too furry." Apollo completely skipped over Percy (Thalia would have too) and focused on Thalia. His eyes brightened. "Daughter of the sky god! Perfect!"
Thalia felt an embarrassing squeak escape her. "No, I don't think-"
"Nonsense! How old are you?"
The dreaded question.
"I- I don't know," Thalia stammered.
When she had been turned into a tree (she preferred not to think about that experience, it kind of sucked and also hurt), she had been twelve, and she still felt twelve. But according to Percy and Annabeth, years had gone by while she was a tree, and now she was nineteen. Nineteen. But she looked somewhere in between.
Apollo tapped a finger to his chin in thought. "You're fifteen. Almost sixteen."
"How do you know that?" Thalia challenged.
"Hey, I'm the god of prophecy. I know things, like when the Sun and the Star will come out or whether McDonalds' ice cream machine is broken and also that you'll turn sixteen in about a week."
Thalia raised her eyebrows. "That's my birthday! December twenty-second."
"Which means you're old enough to drive with a learner's permit!"
The blood drained from Thalia's face. "No," she said. "Nope."
"Yes and yep!" Apollo said, looking happy with his decision. "Maine to Long Island. It's not that far!"
Percy looked uneasy. "The prophecy, about a child of the Big Three turning sixteen-"
Apollo would not take no for an answer. He herded the Hunters and campers alike into the bus and guided Thalia to the wheel.
This means we're going up, doesn't it?
Thalia squeezed her eyes shut in the driver's seat and braced herself for the worst.