The gouvernment has made superhero services illegal in society, The wealthy Deavor Siblings (of DevTech) are working to reclaim their legal status and good reputation. Helen/ Eliastigirl has to go out and save the world whilst her husband stays at home with the children. The Deavor Siblings give Helen a new suit and motorcycle with an integrated camera.
Helen stops a new monorail train from crashing when it starts going backwards very fast. She finds the driver hypnotized by the screen in front of him. He is under the influence of the Screenslaver, a villain who hacks into monitors and hypnotizes people through them. The screen in the train recognizes Helen (wee see this through messages appearing on the screen) when she enters the wagon. Thus it seems like Screensaver can also see from the other side of the screens, in addition to hypnotizing through them.
Screenslaver intervenes during an interview and hypnotizes the TV-host and the control room workers through the screens in front of them. A robotic voice informs Helen that the screens are being controlled by Screenslaver, who is planning to hijack the ambassador's helicopter.
Later, Helen figures out Screenslaver's location when he intervenes at yet another interview, and finds his location thanks to a tracking device that pinpoints where he is broadcasting from. In what seems to be the Screenslaver's headquarters, the walls are covered with the hypnotizing pattern caused by the hypnotizing glasses, which makes it seems like there doesn't necessarily have to be screens. A hooded man with hypnotizing glasses (with a button on the side to activate them) arrives and Helen captures him, discovering a pizza delivery boy under the mask.
The Devtech siblings host a party to celebrate Helens capturing of Screenslaver. Helen ends up in Evelyn Deavor's control room and notices that one of Screenslaver's monitors was connected to her suit cam. Evelyn enters and the two of them talk. Suddenly, Evelyn gets out a pair of hypnotizing glasses and puts them on Helen. She turns out to be the brain behind the hypnosis technology. The pizza boy was being controlled through the screens in his glasses. Evelyn doesn't like Superheroes ( superheroes once failed to save her father from dying). She has been pretending to help Helen. Evelyn makes Mr. Incredible show up, to be hypnotized by the already hypnotized Helen. Their children come to the rescue and the movie has a happy ending, with superheroes reclaiming their legal status and good reputation.
Technology is generally very present in Incredibles 2. There are hidden cameras (in superhero suits, on vehicles, in rooms..). There are also tracking devices, like the one Helen uses to pinpoint the pizza delivery boy's location. In between Helen's scenes, we see how family life is playing out back home. The baby, Jack-Jack, turns out to have a lot of uncontrollable superpowers. Costume designer Edna creates a controller that let them monitor the baby's powers, anticipating, changing and controlling his transformations and tracking his location. There are sensors in the baby's superhero suit to make this process work. At Edna's house, Jack-Jack passes through a three-step recognition process of the hand, the eyes and the voice.