The School Play Surprise (Scooby-Doo Reader No. 19)

Scooby-Doo is an "Ameri-canine" icon the most beloved cartoon pooch of the past three generations. Yikes! A mysterious message sends Scooby and Shaggy to the school auditorium but ruh roh! Looks like something spooky is going on -- first Fred vanishes into thin air and then they see witches lurking back stage! Can Scooby and the gang solve this mystery before its curtains for them?