The film begins with a Brownie troop visiting a doll manufacturing company called Dolls Inc., owned and operated by the seemingly kindly Mr. Franz (John Hoyt). As the girls tour the factory, they see a number of very lifelike dolls stored in glass canisters locked in a display case on the wall. These are part of Mr. Franzâs special collection.
Sally Reynolds (June Kenney) answers a newspaper advertisement for a secretary; Franz's previous one has mysteriously vanished. Although she is concerned about his obsession with his dolls, she reluctantly agrees to take the job.
She soon meets a traveling salesman, Bob Westley (John Agar), who introduces himself as the best salesman in St. Louis and immediately sets about attempting to seduce her. Their relationship become serious enough that Bob persuades Sally to quit her job, promising to break the news to Franz.
The next day however, Franz informs Sally that Bob has gone back home to take care of business and that she should forget him. She, however, is unwilling to accept this and goes to the police with a theory about Franz' role in her boyfriend's disappearance ("He made Bob into a doll!"), but Sergeant Paterson (Jack Kosslyn) is skeptical. Franz has developed a machine which can shrink people down to a sixth of their original size. He then uses it on anyone who tries to leave him. When he finds that Sally plans to quit, she becomes his latest victim.
Franz has already miniaturized at least four other "friends". They are stored in suspended animation (which he has also invented) in glass jars in a display case in his office. After a reunion between Sally and Bob, Franz reveals how the process works and why he miniaturizes people (it seems that he developed a strong phobia against being alone after his wife left him). Periodically, Franz awakens his captives to enjoy parties he throws for them.
During a welcoming party for the two newcomers, Franz has to deal with full-size friend and customer Emil (Michael Mark). The prisoners try, but fail to call for help. However, Sergeant Paterson begins investigating Franz, as many people he knows seems to be missing. After Franz is questioned by Paterson, he panics, announcing to his miniature prisoners that he plans to kill them and himself before he can be caught. He takes his troupe to an old theatre, supposedly to test his repairs on Emil's marionette. There, he throws one last party, making his captives act out Dr. Jekyll and Mr. Hyde for him.
Bob and Sally manage to escape and make it back to Franz's workshop. Franz tracks them down, but not before they are able to return themselves to normal size. They leave to fetch the police, despite his feeble pleas. The fate of the other prisoners still miniaturized and frozen is not revealed.
Director Gordon's daughter Susan Gordon appears as a young girl, and another of Gordon's films is referenced when a scene from The Amazing Colossal Man is shown at a drive-in.
What size are Bob and sally at the end
Normal size