In her hidden lair in the Rockies, the "most brilliant, most dangerous woman on Earth," Medula, is informed by her two lieutenants that the computerized Will Booster is ready to be tested. Elevating a parabolic dish through an opening in the mountain, they fire a beam at Elmwood City. Women throughout the town are possessed by Medulla's will, with their eyes developing a white glow as they repeat their mantra, "We are with you, Medulla..." in a monotone. Turning their gaze on the men, they make them disappear.
Satisfied with the test results, Medulla increases the beam's power and broadcasts it across North America. The men Medulla's women dematerialize reappear at Medulla's headquarters, where she digitizes them and stores them on tape "so that women may rule the world, unopposed." The Superfriends, using tracking devices they've attached the U.S. President, discover where the men reappear and journey to Medulla's lair while Superman remains at the Hall of Justice to use their computer to figure out a way in. Wonder Woman and Jayna come across some women entering through a seemingly-unguarded opening and follow them in. "They're sneaking in. Excellent! I'll let them get away with it," observes Medulla when she spies them on her monitors. Ambushed by her lieutenants, the heroines are brought before the gloating Medulla, who announces from a mezzanine, "The two of you will be possessed by my Will Booster and, together, you will dematerialize the rest of the Superfriends!" After falling victim to her Will Booster rays, the pair turn and walk out of the assembly hall. Back outside, Zan is soon surprised and dematerialized by Jayna, while Batman and Robin disappear beneath the gaze of Wonder Woman. While Aquaman is reporting to Superman, he is dematerialized by his two former teammates. Medulla then orders them to go to Metropolis and "deal with Superman."
Landing the Invisible Plane on the plaza outside, they boldly stride into the Hall of Justice. Wonder Woman and Jayna spot Superman standing at the monitor screen and zap him from behind. Raising their arms in triumph, they report "We have conquered, Medulla! The world will soon belong to you!" "Yes," rejoins the villainess, "Superman has joined his friends!" Unbeknownst to them, Superman had witnessed their attack on Aquaman. He had substituted a lifelike statue for himself at the monitor. Thinking she has all the Superfriends, Medulla departs for the U. S. Capitol building in Washington, D.C. to take over the country. Meanwhile, Superman flies to Medulla's HQ and rematerializes the male Superfriends. Batman and Robin surprise Wonder Woman and Jayna and, when they try to re-dematerialize the men, use mirrors to bounce their rays back back on the women. The reflected rays cancel themselves out. Freed, a grateful Wonder Woman leads Aquaman to the House Chamber, where Medulla is issuing orders to her deputies for her plan to rule the world. Escaping their interruption, the villainess vows from the House dais, "You'll never stop me! I have millions of women under my control!"
Wonder Woman states "I know just how to stop her," and departs in her Invisible Plane. Her jet arrives back in the Rockies long before Medulla's Bell 47J helicopter. Making her way to the computer console on the mezzanine, Wonder Woman dons the headset and directs a beam at Medulla's craft. Falling victim to her own Will Booster, Medulla flatly replies, "Yes, Wonder Woman, I am headed for Metropolis police station..." Back at the Hall of Justice, Wonder Woman summarizes the situation, “Medulla’s method of controlling women and putting them in power was wrong. Only gradually, a step at a time, can social customs change – no matter what they may be.” “Perhaps now she realizes her method of controlling women for her own personal power was wrong?” adds Superman.