S2·E48 The Joker's Epitaph

The Joker is now Vice Chairman of the Gotham National Bank, due to an unsuccessful plan of Batman's. He installs his robots as tellers, and despite his criminal past, seems to be running things in perfect order. The Dynamic Duo realize they will have to trick him into making a mistake in order to remove him. They go to work on a plan to gain control of his robots. But that plan is jeopardized when, due to an odd turn of events, Batman's true identity Bruce Wayne is declared mentally ill and hauled off in a straight-jacket.