Barney Barrows

A janitor at the headquarters of the Gotham City Police Department, possessed by a violent hatred of criminals and unhappy because he is not sufficiently intelligent to pass the "mental examina­tions" required for becoming a police officer, who is accidentally exposed to " a tremendous burst of strange radiation" as the result of "a freak explosion" in the police department laboratory and who regains con­sciousness hours later to discover that the "accidental burst of freak radiation" has somehow "stimulated [his] brain-cells" and transformed him into "the world's greatest mental giant."

Now gifted with "titanic brain-power" but still seized by the same unenlightened lust for vengeance against criminals that had characterized him as a "weak­ minded" janitor, Barrows uses his newly acquired intellectual abilities to deduce the secret identities of Batman and Robin and then, by threatening to make his knowledge public, forces them to serve as his unwilling assistants in an all-out war against crime that has as its end the deliberate assassination, rather than the capture, of criminals.

Batman and Robin manage to outwit Barrows long enough to apprehend the Metals Mob - a gang of criminals specializing in the theft of rare metals­ without allowing the former janitor to harm the crooks, and eventually the effects of Barrows's mind-expanding accident wear off and, lapsing into unconsciousness once again, he awakens bereft of his enormous mental powers - without any recollection whatever either of the Dynamic Duo's secret identities or of any of the events that took place following his accident - and returns to his janitorial duties at police department headquarters.