It is 1942. War Department secretary Diana Prince is attending a gala dinner in support of the American war effort. The President himself is there – Franklin D. Roosevelt. Diana is sitting next to Major Steve Trevor, the man she loves, but all he wants to do, it seems, is talk about Wonder Woman! Needing to visit the Powder Room, Diana excuses herself. ‘But since all you have been doing for the last ten minutes is talk about how wonderful Wonder Woman is, I doubt you will even notice I’m gone,’ she thinks, ruefully.
Before Diana can enter the Powder Room, a crazed isolationist newspaper political columnist called Maxwell Stanhope attacks the President with a stiletto dagger. Diana runs into the Powder Room and then instantly re-appears as Wonder Woman. The amazing Amazon captures the deranged columnist before he can harm Roosevelt. After the fracas is over, the President thanks Wonder Woman personally for saving his life.
Unfortunately, Wonder Woman’s unexpected appearance at the gala has an unforeseen effect. Also in attendance is beautiful, wealthy debutante Priscilla Rich. Suddenly seeing Wonder Woman in action like that triggers the re-emergence of the buried side of Priscilla’s personality known as The Cheetah. Disoriented and distressed, Priscilla staggers to the Powder Room but the face which glowers back at her from the mirror on the wall there is not her own. It wears the sneering expression of The Cheetah. ‘Let me have control again, Priscilla,’ the reflection seems to say. ‘You know we have a lot more fun when I am in charge.’ Fleeing the building, ‘Priscilla’ tells her chauffeur to drive her home. But by now this woman is no longer Priscilla Rich. The Cheetah is back in control. Wearing her special Cheetah body-suit, the villainess luxuriates upon her king-sized bed, contemplating how she will make use of her new weapon – a wrist-mounted device for firing ultra-sharp darts.
The following afternoon, The Cheetah leaps from a bridge over the Chesapeake and Ohio Canal onto a sight-seeing boat where she proceeds to divest the tourists of their valuables, threatening them with her claws. Wonder Woman happens to be flying overhead in her robot plane. When the Amazon confronts her old enemy, The Cheetah fires a volley of sharply-tipped darts. After Wonder Woman deflects the darts using her Amazon bracelets, The Cheetah punches her foe into the canal before releasing another round of darts. Unable to react as quickly in the water, the Amazon cannot deflect all of the missiles. One dart strikes her forehead, stunning her, so that The Cheetah is able to get away.
But worse is yet to come. The Cheetah had attacked the tourist boat hoping that Wonder Woman would show up, for she had coated her darts with an indelible ink which would only appear when viewed through infra-red lenses. Having noticed how Wonder Woman had always seemed to be on hand to deal with cases of espionage in and around Washington over recent months, The Cheetah had deduced that in her secret identity Wonder Woman must work at the War Department. The Cheetah makes a list of all the ‘WACS’ (Women’s Army Corps personnel) and ‘WAVES’ (Women Accepted for Volunteer Emergency Service) working at the War Department who match the Amazon’s height and build. She then dons a pair of special contact lenses and spends days stalking the streets of Washington, spying on her list of subjects. In due course, The Cheetah discovers the mark made by her treated dart on Diana Prince’s forehead. The villainess proceeds to invite Wonder Woman (via a letter sent to Lieutenant Prince) to the recording of a public service film being made by the Junior League Committee for War Work. (The Cheetah had simply attached Priscilla Rich’s name to a Junior League Committee letterhead.) The film itself is a legitimate appeal in support of war bonds, but The Cheetah plans to plant an explosive device in the studio camera. ‘The sign which warns that the camera is ‘rolling’,’ The Cheetah explains in a soliloquy, ‘will be the detonator. When the Amazon muffs her lines or the Director calls ‘Cut!’ the camera will stop’ and then the device will explode. After recording her plan carefully in in her diary, the Cheetah goes to bed.
However, the next morning, it is Priscilla Rich who wakes and reads to her horror in her diary about The Cheetah’s discovery of Wonder Woman’s secret identity as Diana Prince and about the TV studio assassination plan. ‘What can I do?’ she wonders. ‘If I report what’s going to happen, I’ll be locked up as a madwoman. If only Wonder Woman did not exist, then nothing would trigger The Cheetah side of my personality and I could live a normal life.’ Priscilla decides to invite Diana to her home. When Lieutenant Prince arrives, Priscilla holds up a pocket watch and asks her guest to look at it. Diana obeys and Priscilla quickly hypnotizes her. (Since Diana has not been living in the western world for very long, Priscilla had surmised that the Amazon would still be naïve and trusting. ‘Perhaps,’ the debutante muses, ‘she has never even heard of hypnotism!’) Priscilla commands the hypnotized Diana to forget all about the existence of Wonder Woman.
For a week there is no sign of Wonder Woman anywhere. On the day of the filming, Steve Trevor decides to go to the studio in Wonder Woman’s place. Priscilla is present at the long-disused movie studio in downtown Washington when Trevor arrives. Seeing that her plan to prevent The Cheetah’s bomb from going off has failed, Priscilla attempts to persuade Diana Prince that she is really Wonder Woman so that she can save Steve Trevor’s life. When Diana refuses to believe her, Priscilla pretends to attack her with the dart-firing bracelet. Diana instinctively moves to protect herself with her Amazon bracelets. ‘You see,’ cries Priscilla, ‘you are Wonder Woman!’ Her memory restored, Diana turns into Wonder Woman, which triggers the re-emergence of The Cheetah. The two women tussle and Wonder Woman knocks The Cheetah unconscious with a studio back-drop.
The interview with Trevor, meanwhile, has started. The director does not like Steve’s military uniform and considers shouting ‘cut’. Luckily, the director’s assistant says that Steve looks just right in his uniform. But then a mistake is made with the cue cards and the director does shout ‘Cut!’ Wonder Woman bursts into the studio and throws the camera through an open doorway so that the bomb explodes in an empty corridor. By now, The Cheetah has revived and attacks Wonder Woman again but the Amazon defeats her once more and subdues her will by encircling her with her magic lasso. Wonder Woman informs her captive that she will be taken to Transformation Island, a rehabilitation centre run by the Amazons.