39. Violence is blue
A prophecy comes to pass following a household accident.

Meanwhile, Dawn was moping around the lobby. "'Don't do this.' 'Don't touch that.' 'Don't kill this.' 'Don't fuck that.' Why couldn't Faith be my sister instead... Cool!" She'd spotted Angel's weapons cabinet. She was fiddling with a state-of-the-art crossbow when suddenly there was a crackling of energy behind her.

With a surprised "Eeep!", Dawn spun around and within a fraction of a second, her vampire senses told her three things:
1) A boy wearing animal skins had just appeared out of nowhere.
2) He was kinda cute.
3) In her surprise, she had accidentally triggered the crossbow, killing him instantly.