Wonder Woman thwarts another scheme by Baroness Paula Von Gunther - this time to monopolise America's milk supply.
Diana Prince is missing, causing Steve Trevor and General Darnell to be concerned. They are worried that Baroness Paula Von Gunther might be involved, but are relieved to find a report claiming that she was killed in the electric chair a week earlier.
We then learn what befell Diana a few days earlier. She came across a woman and her daughter who is starving because she can't afford to buy milk. Diana promises to buy milk for her, but learns that the price has become incredibly high. She investigates and finds that the International Milk Co. has bought up all of the nation's milk and is pouring much of it down the drain and raising prices beyond what is reasonable. Diana confronts Mr. De Gyppo, the president of International Milk, but after making a mysterious phone call he activates a trap door and Diana is captured.
Her captors try to get Diana to give up information about who sent her, but she refuses to comply. Eventually they decide to put her in a tank of milk to drown, but while trapped in the tank she changes into Wonder Woman and tears a hole in the tank, causing the milk to drain. She then captures the men in her Lasso of Truth and forces them to reveal that they are working for a "Dead Woman." Wonder Woman calls Steve, who decides that the dead woman must be the Baroness, though he can't figure out how she escaped death. He speaks to the doctor who administered her autopsy and, using a lie detector, gets the doctor to admit that, though he saw that the Baroness was in fact dead, he agreed to give the body to some of the Baroness's friends when the autopsy was complete.
Meanwhile, Wonder Woman leads a parade staring Etta Candy and her Holiday Girls in protest of the International Milk Co., with the intent of drawing the Baroness out of hiding. Sure enough, one of the Baroness's slaves leads Wonder Woman down an alley where a group of men capture her and chain her up. They believe that chaining her robs her of her powers, but fail to realize that the chains must be forged onto Wonder Woman's bracelets to have that effect.
Wonder Woman acts weak in an effort to lure out the Baroness. She also calls for Etta Candy and the Holiday Girls to infiltrate the International Milk Co.'s headquarters. They do so, but the Baroness, who was revived by an electric device, had warned De Gyppso that they might arrive, so he is ready for them and traps them. At the same time, the Baroness's men chain Wonder Woman to the back of a milk train that they intend to roll down a hill into a pile of explosives, but only after the Baroness arrives and explains that she is robbing American youngsters of milk so that, in twenty years, they will be weak and Germany will be able to defeat them.
Steve Trevor arrives at the International Milk Co.'s headquarters and frees the Holiday Girls and a fight ensues. Meanwhile, Wonder Woman gives up her ruse and breaks the chains holding her. She goes to the headquarters and joins in the fight, quickly turning the tide. She lassos the Baroness and gets her to sign a confession regarding her involvement in intentionally ruining the U.S. milk supply.