Professor Gibbs was a fusst old scientist often described as 'loony' by those who knew him. Funded by Richard Russell, Professor Gibbs invented a machine that was capable of turning a person invisible. Needing a test subject, Gibbs put an ad out in the paper. Unsurprisingly, most of the responses Gibbs received were of the joking variety, but one, from a model named Kitty Carroll, was serious and Gibbs hired her on the spot. The experiment was a success and Kitty was turned invisible, but the invisibility was not permanent and would only last a few hours.
Much to Gibbs' chagrin, not only did Richard Russell not believe that the machine worked, but Kitty misused her new abilities to get playful revenge against her employer Mr. Growley. Things went from bad to worse for Gibbs when notorious criminal Blackie Cole read the very same ad and sent his three minions to try and acquire the invisibility machine. Although they succeeded in stealing the machine while Gibbs was away from home visiting Russell with Kitty to prove that his device worked, they could not make it work.
Gibbs succeeded in convincing Russell that his device was a success, but then Hammerhead and Bill returned and kidnapped Gibbs, taking him and Kitty (now finally visible again) to Blackie's hideout in Mexico. Before the gangsters could force the Professor to tell them how to operate the machine, Kitty drank pure alcohol which acted as a catalyst with the effects of the machine and turned her invisible again, allowing her to defeat the criminals.