Minutes after where the first film left off on, the Parr family confronts The Underminer as he makes his way towards City Hall while also grounding buildings and robbing the city bank. While the villain managed to get away, the Incredibles manage to stop the drill just on time with the help of Frozone. But they are then arrested for intervening in such an incident and for destruction of property. Rick Dicker of the "Super Relocation" program tells the couple that he is being shut down due to this event and that the Parrs will be left on their own but wishes them luck.
Lucius meets up with Mr. Incredible and Elastigirl to inform them that they are being contracted by Winston Deavor of DevTech. When they arrive to meet him, they are greeted by Winston and his sister Evelyn Deavor Winston proposes a plan to help give back the superheroes public support by setting up missions and publicity stunts to better their reputation. He enlists Elastigirl due to being the least destructive out of the three to which she agrees. Winston offers the Parrs a new home as a sign of appreciation and giving Elastigirl a new suit and new Elasticycle, leaving Mr. Incredible and the kids; Jack-Jack, Violet, and Dash, on her first mission.
Flying out to New Urbrem, Elastigirl stops a newly built monorail train from crashing after it unexpectedly goes backwards at high speeds. She discovers that the train driver was under the influence of the Screenslaver, a villain who hypnotizes people through any monitor he hacks into. During an interview she encounters the villain again by exposing his plans to kill the Ambassador by hijacking the escort helicopter she's on but Elastigirl quickly comes to her rescue.
Elastigirl's recent actions have caused a movement of superheroes stepping out into the public, wanting to help out others like they did in the past. These include the likes of Voyd, He-Lectrix, Reflux, Screech, Krushauer and Brick. She manages to figure out the Screenslaver's location by pinpointing the signal where he broadcasts from another TV interview. Elastigirl arrives at the scene with the Screenslaver attempting to escape but manages to capture the villain, although the suspect claims to only sell pizzas.
Meanwhile, Bob struggles to take care of the kids. Violet becomes very distraught when her crush Tony Rydinger does not remember her as Dicker wiped out his memories after he found out she was a superhero. Dash struggles with regular school work which leaves Bob frustrated as well. And after fighting a raccoon Jack-Jack's multitude of powers start to show even more with Bob not able to figure out how they work. But he eventually manages his job as a parent, going the extra mile to help his two eldest kids and by having Edna Mode babysit Jack-Jack, who ends up giving Bob a way to control the baby's powers.