At first the children of class three are thrilled that Ms Wiz is back even if her black hair has turned blonde. But soon they discover that the new Ms Wiz has changed more than her appearance. She is not Ms Wiz but her evil twin sister and she's kidnapped Podge and turned him into a pumkin.
Used availability for Terence Blacker's Ms Wiz and the Sister of Doom
July 1999 : UK Hardback
July 2000 : UK Paperback