It features Batman and a few university students trying to crack a decade-old case, and has the earliest origin story for the Joker.
Batman and Robin have been asked by Dean Chalmers, head of Gotham University, to volunteer as teachers for his criminology class.
Over the course of a month, Batman teaches the students many things and decides that they are ready for a real case—that of "The Red Hood".
Batman questions him and finds out that the school gardener had captured the real Red Hood and left him locked inside a tool shed.
The Joker explains that years ago, he was a lab worker who decided to steal from the Monarch Playing Card Company.