Mansour and friends are interested in Teacher Ali's latest invention but Teacher Ali can't seem to remember what it's for! The boys soon discover that Teacher Ali has invented a memory-zapper which can wipe out someone's memory one moment, and return it in the next. The boys have fun with it, but when Mansour notices a pair of thieves breaking into the museum, he decides it's time to put the memory-zapper to even better use.
