A small-time thief named Benny finds an ancient lamp during a robbery. Batman and Apache Chief apprehend the crook... but observing from a distance is Mxyzptlk. He decides to get into the act by playing the part of a genie... who zaps the crook away... and from that point forward the two go on a crime spree. Batman gets the last laugh on Mxyzptlk, though.
