It was the night of the attack. Billy didn't care who died, as long as Sidney died, so sadly, he didn't care if his twin sister died, obviously because he stabbed her. He just looked at her with a smirk as she looked at him with a look of pure betrayal as she held her stab wound What's the matter, sis? You look so betrayed. I say as I yank off my necklace that matches yours and throw it at you