From 2001 - Marti Noxon on Buffy's original ending
We have said, I think, that Buffy would never go beyond five seasons. Originally Joss’s plan was that at the end of Season Five, Sunnydale was going to get sucked into the Hellmouth and that was going to be the end of it. Obviously, as you know, we’re continuing here in the States, so that didn’t happen.
Remember the scene where Joss played your brother and did that ridiculous Dance of Joy? How could you keep a straight face during the shoot - in other words, how many takes did it take? A lot! But I didn’t know it was him. He was keeping it a secret.
Do you think knowing it would have made it funnier? No, I knew after a little while, but HE wanted it to be a big surprise, so he even had his make-up done in another make-up trailer. And I remember, cause the make-up artists were having to cater for his needs, so the whole time I was in make-up I kept hearing “We’ve got to do Numfar over at the brown trailer” and I’m thinking “Who the FUCK is this Numfar? And why is HE getting special treatment, more than I am?”, And then we went to a rehearsal, which was out in the woods, and I was late and they were waiting for me. And usually before rehearsals I go up to the other actors and introduce myself, but I was late this time, so I couldn’t. And then I saw Numfar and he did his dance and I thought “Oh my god! Who IS this guy?” I thought he was trash. And… how did I find out? Umm…
He yelled “CUT!”? He smiles, Yeah, right. That’s very funny… I was standing with David Boreanez, and he was like “Oh my god! Do you know who that is?”, and he told me, and Joss was really pissed that David told me.
From a Joss Whedon interview conducted back in 2005
Could Serenity take place in the same universe as Buffy but the monsters were taken care of long ago?
I think you could make an argument for it, but I wouldn’t. The only thing we ever thought of doing is having a drunken and very miserable Spike at a bar just sitting there going, ‘Nothing changes. Trust me, nothing changes.’ That would’ve been in our decadent era. That would have been like season six. But no, I have to think about them as totally separate because they have different sensibilities and they have different sets of rules. It’s very important that Serenity be grounded. I had to go into outer space to come back down to earth but Buffy was a fantasy, a metaphor for rites of passage of our lives and Serenity is something else.