Brad Bird will be taking the helm again of an "Incredibles" film, which is scheduled to arrive on June 21, 2019. It is speculated the "The Incredibles 2" plot will center on the youngest member of the Parr family, Jack-Jack, who will be in his pre-teens.

There is really not much information available with regards to the storyline of the upcoming "The Incredibles 2." But according to rumors, Jack-Jack will be old enough to understand a little about life, and will be rebelling against his family, and the fight will be between him and his older brother, Dash, as previously reported.

Crossmap added that Samuel L. Jackson mentioned something about the youngest family member during an interview in the past. He said, "I'm looking forward to what Jack-jack turned into."

Another theory circulating is that Syndrome will be back and will try to control Jack-Jack, who in turn will rebel against his family.

There is also a theory with regards to the release date of "The Incredibles 2." By the time it hits the screen, there will be a 15-year gap in between. Some believe that it has something to do with the revenge of Syndrome against Mr. Incredible. However, it may also be that Bird was just busy for the past several years and could not concentrate on creating a great plot for its sequel. After doing the first movie, he directed "Ratatouille," "Mission: Impossible – Ghost Protocol" and "Tomorowland."

He also took part in different movie projects in different capacities, which include "Up," "Toy Story 3," "Brave," "Monster University" and "Inside Out."

It is speculated that Jackson will be back to do the voice for Frozone, the family friend of the Parrs. Syndrome is also rumored to be back, although it is not sure if he will be the main villain or will be joined by another.