The Three Dimwits, trying to charge an old car battery, pour in a variety of chemicals, then attach a sunlamp to it as a power source. The resulting "purple ray", they find, has a strange effect upon people: it affects the secretions of the bodie's gands, resulting in changes in poise, conduct, and even in the brain itself!; "Trigger" Tom and his gang succeed in stealing the purple ray. Flash successfully gets it back, but the ray plays on him and the Three Dimwits, giving them the Flash's personality and giving the Scarlet Speedster theirs!; After regaining his personality, the Flash tracks down "Trigger" Tom and his hoods, all of whom have been taking advantage of a "Flash-less" city, and destroys the purple personality ray for good measure.; People stream into the Three Dimwits, wanting to bathe in the purple ray, wanting to become someone else. The nitwit's fame reaches far and wide, including to the criminal element, who endeavor to get in on the action. The Flash must deal with that problem as well as the complaints from people whose personalities have been altered.