Okay so I've seen the first season and a half of Buffy but none of the rest of it, so that first bit is off the table.

Um, geez, though-- at some point in the ensuing seven seasons Buffy is torn between Angel and Spike, her sister starts figuring into things, Giles falls in love with a woman named Jenny who eventually dies, I'm sure Joss Whedon randomly kills other people off as he feels like it, Willow has a lesbian relationship and I think becomes a witch...? Also possibly evil?, everyone continues hunting down vampires and kicking ass, there is a musical episode which I keep meaning to watch, and there is great fandom dispute about which seasons are terrible and which seasons are wonderful. Three is supposed to be awesome, and five or six or seven is supposed to be the worst...?

That was desperately disjointed.