The Invisible Woman

Dr. Dudley Plunkett conducts experiments with colored chemical containers in his Washington, D.C. lab. Chuck the chimpanzee touches the formula and becomes invisible, prompting Sandy Martinson to witness the event. A spill leads to Sandy being exposed to the liquid, turning her invisible as well and fearing for her future.

Plunkett discovers that Sandy can appear passably visible again with makeup, a wig, and sunglasses. He arranges for her to continue reporting, and her editor assigns her to a new art gallery theft story. Sandy resolves to use her invisibility to aid the investigation, even contemplating going nude for an advantage.

Sandy finds a key on the floor of the art gallery vault that points to a health club. There she watches the thieves in a steam room and learns that Carlisle Edwards is behind the scheme, with two henchmen planning to steal Cleopatra's scepter next. The thieves sense her presence and pursue her, but she escapes.

Plunkett calculates when Sandy will reappear and plans to demonstrate the invisibility formula to the Institute board in his lab. He hopes to reveal the proof at the moment of Sandy's return. At the meeting, he discovers that Chuck's empty cage had been replaced with a different chimpanzee, undermining his claim that Chuck had become visible again.

After the board hearing, Dr. Farrington admonishes Plunkett for lacking evidence. Sandy decides to keep her invisibility a secret so she can continue helping as a reporter without revealing the source of her power.

Sandy informs the police about the planned theft, but they remain skeptical. She resolves to go to the museum with Plunkett to impede the crime and begins sneaking in, invisible, to spy on the criminals.

Invisible and unseen, Sandy uses her Cleopatra persona to frighten the thieves. They chase her into a sarcophagus that closes and traps her inside. Plunkett rushes in to help, but the thieves manage to grab the scepter and escape with the danger escalating.

A security guard captures the criminals, giving Sandy a moment to apply makeup and reappear. The thieves break free from pursuit and continue their desperate escape, while the scepter remains a focal point of the conflict.

The thieves kidnap Sandy and force her to drive their getaway car. Police pursue them through the streets as the criminals shoot at officers, while Sandy remains a high-stakes pawn in the chase.

In the back of the car, Sandy removes her makeup to become invisible and reclaims the Cleopatra identity. She convinces the thieves to abandon their weapons and surrender, then ferries them to the police station where the scepter is secured and the culprits are arrested.

Back at home, Sandy proudly shows her front-page story to Plunkett about the museum robbery foiled. He then receives a letter from Dr. Farrington firing him from the Institute, jeopardizing his ability to pursue invisibility research.

Sandy accompanies Plunkett to the Institute to interrupt a board meeting led by Farrington. In invisible form, she performs pranks that mystify the board, convincing Farrington to reinstate Plunkett and resume his work.

The newsroom hosts a celebration as Sandy and Plunkett toast with colleagues. Gillmore arrives with a rival newspaper, pointing out the headline and asking why the 'invisible woman' wasn’t seen. Plunkett replies that it is very difficult to see an invisible woman, and they toast together.