I dont own Percy Jackson, But Lily is mine. Also this is inspired from the "Age of the demi-gods" speech from Luke in the movie.
"Can you repeat, this insane plan for me one more time?" Lily asked, looking at her half-brother. And he did, Luke told her of his plan, to end the rule of the gods, to claim the world themselves. The Age of the Demi-gods.
"well?" Luke said when he finished speaking. He hoped she wouldn't tell her friends, or anyone. The plan was still in the works, Luke knew that if his plan was found out, well, it wouldn't be pretty.
"Your asking a lot, your asking me to abandon everyone, Luke. Your asking me to leave Percy, Annabeth, Grover and the entire camp! They took me in, they became my family! And what about my father? Our father? What about the gods? What will happen if they find out? We'll be killed!" her arms were moving as well as her mouth. She waved them, as if they would make Luke see reason, see his plan was crazy.
"So, your saying no?" Luke asked, feeling a bit dissapointed. Him and Lily, they were sibblings. He had assumed she would agree. They both had the same fatal flaw. They both desired power. Absoult power. All Hermes kid's did.
" I didn't say that, I said its insane. But, if your serious, you won't blame me if we get caught, or back out when it gets tough, well I guess. Maybe. There's a risk, but if your offering me power,absoult power, then I might actully think about it." as she talked, she kept her hands busy, fiddling with the strings on her shorts, playing with her hair. She was the poster kid for ADHD at that moment.
He nodded, "Ask them." there was no need to clarify who, Lily knew. He wanted Percy, Annabeth, and Grover. He wanted them on his side. They were some of the most powerful demi-gods of this generation. They would ensure victory.
Lily shook her head, making a 'no'. 'I won't ask them untill I know who's side I'm on." Luke nodded, he had seen Lily like this before, hestiant making sure things would work out for her in the end, he's seen her like this, or when she deals on impulse. He's seen her becuse he's know her longer than Percy and Grover and Annabeth. He's known her longer than any of them have.
When he's facing Jackson on the roof, he knows what side she's if she doesn't. He saw as she doesn't look away before he knows that even if she wanted power, she was to scared to take what was in front of her. Becuase she wasn't sure who would win. She didn't know.