Thank you for sharing this video. I have never heard of Mark Stay before but I will have to check out some of his work (once my current pile depletes a bit lol).
The Witches was the first "series" I read. In fact, Wyrd Sisters was my first ever venture into Discworld. My English teacher at school recommended it as we had just finished studying Macbeth and he said it was a hilarious parody. Going straight from intracatly studying Macbeth to Wyrd Sisters was a wild ride haha.
Love all his first edition copies he has as well!