The woman that hires Mr. Incredible turns out to be the minion of the fan (Buddy, now known as Syndrome) that Mr. Incredible spurned, now grown up and after revenge. His plan is to create an unstoppable robot by pitting old superheroes against them, thus upgrading it everytime a superhero defeats it. He will then unleash it upon a city, then save the city from the robot by using the remote on his arm, and be hailed as a new superhero. Meanwhile, the rest of the family arrive on the island in a bid to save him. They do, and travel on a rocket (courtesy of a converted assistant) to stop Syndrome's robot. They do this by making it stab itself with tentacles. The family goes home and find Syndrome with Jack Jack. He flies with Jack Jack to his plane, but Jack Jack now has powers, and unleashes them on Syndrome. Helen rescues Jack Jack and Syndrome gets killed by getting sucked into the aeroplane's engine. Super heroes come out of hiding, and a new enemy called The Underminer comes out of the ground threatening the city, making us believe that there might be a sequel.
Mozza
Answer: IMDb just says additional voices, nothing specific.
Shannon Jackson