Equal Rites: Terry Pratchett

Book III of Discworld. Every world has its rules - even a flat one carried by four elephants riding on a giant turtle. That's why a dying wizard is searching for an eighth son of an eighth son on whom to bestow his wizardly powers before meeting Death (in about six minutes.) Unfortunately it is quickly discovered - thought not quite quickly enough - that the newborn babe the wizard anoints just before bidding Discworld adieu is, in reality - a girl. What's done cannot be undone - despite old Granny Weatherwax's attempts to bring the child into the witchy fold - and little Esk is now a wizard, through and through. And she's destined to bring chaos, confusion and mayhem to the all-male faculty of Ankh-Morpork's Unseen University - who are all fairly addled to begin with. Cover art by Ben Perrini.