Vampires and sunlight
details | 3 comments | suggested by Jess
We first learn that vampires can be killed by direct sunlight in 1.02 The Harvest, when Buffy says:
Xander: “So, what else?”
Buffy: “What else what?”
Xander: “For vampire slayage.”
Buffy: “Oh, fire, beheading, sunlight, …
