Bellatrix was tentative, wary of other students. Illogical though it was, she felt that if she became comfortable with any of them and let her icy composure slip, they would run off to report her to her parents. That there were only a handful of students in the school that even knew her parents didn't occur to her.
Over breakfast one morning, she let herself slip, just a little. A boy slipped into the seat next to her, smiling.
"Who are you?" she asked immediately. No one had ever taken the initiative to sit next to her before.
"I'm Rodolphus. You're Bellatrix Black, right?"
She nodded, and was surprised to find the tiniest of smiles growing on her face.
"Hello," he said, then he poured his juice and that was the end of it.
He was the first student who she ever smiled at.
In a way, years later, Bellatrix considered him her very first friend.