It's on wikipedia. Professor D had a wanderful relationship with that other wizard who he was friends with while searching for the 3 itemz before thier famous duel.
@Vivi, For the ultimate experience in movies that deviate from the book, I recommend Stephen King's The Running Man and The Lawnmower Man.
Omg, let me describe The Lawnmower Man: a fat guy is hired to mow some guy's lawn. The homeowner looks out and sees fat guy is crawling around on all fours alongside the autopilot lawn tractor, and he is EATING the grass that comes out! What the...? King was totally whacked out on skunk weed.
SpoilerOh, and the homeowner gets eaten too.
As for The Running Man...