Buffy: No, wait. I’m not buying, you guys. Remember the hellmouth? Mystical activity is totally rife here. This to me says demon.
Giles: I’d like to think you’re right. A demon is a creature of evil, pure and very simple. A person driven to kill is...is...um...it's more complex.
Willow: The creep factor is also heightened. It could be anyone. It could be me!
[They all look at her.]
Willow: It's not though.