The Black Widow uses her cerebrum short-circuiting device to rob bank after bank in Gotham City. Batman and Robin soon catch up with her, but actually capturing the villainess proves harder than expected. Despite her nerve paralyzer spray, and two remote-control dummies that try to throw the Dynamic Duo off course, they finally make it inside the Black Widow's lair. But soon after entering, they are trapped in a giant web with two deadly black widow spiders.

The Black Widow adjusts her cerebrum short-circuiting device to successfully alter Batman's brain. With Batman powerless to resist, and Robin captured, she disguises herself as the Boy Wonder and brings along a dummy Batman to rob another bank. Commissioner Gordon initially believes Batman is setting a trap for the villainess. But when word comes of the successful robbery, the commissioner puts out an all-points bulletin to bring in the Caped Crusaders dead or alive.