Tell us about the alien monster.

My father is an astrophysicist at Harvard and he has disowned me based on that episode (laughs).

No, he actually just requested a tape of so he could play it in his lecture. It isn�t based on anything. I think the mythology came out of Jane Espenson�s brain.

I think the alien mythology is just about myth, and I think it was Jane Espenson,�s idea - those specific phenomena occurring- just a blob monster.

Goo as well.

Goo, dangerous goo. [It�s a] slug monster from outer space. Yeah, I said it.

I think what�s interesting about that [episode] to me is there�s two different kinds of life-threatening things happening. Every episode of Buffy has something life-threatening - or it wouldn�t be interesting. But what happens when you have a blob-like slug monster that can suffocate you with slime, and then you have a tumour?

They�re both terrifying and they�re different kinds of terror. You don�t want the slug monster to be less scary, but there�s something really scary about our real monsters and the things that could really happen to us. I think it is a delicate balance, but you have to keep them within the same reality where both of those things are frightening and they can cross paths and play off each other.