Grace pulled her gaze back.

Christopher plopped down right next to her, glanced at her a couple of times, and she noticed.

"What's up?" she asked.

"Well, you know I'm not as smart as you and my brother when it comes to studying. I've got a few physics problems I don't really get…"

Grace paused in surprise, but before she could say anything, Christopher added, "I wanted to ask my brother for help, but he just told me he was busy and said I ...