No, Fantastic Four 3 is not happening, although Jessica Alba has just joined a movie with a slight connection. Alba will lead An Invisible Sign of My Own, a film that revolves around a young woman who has retreated from the world and is consumed by numbers and math. Things begin to change when she becomes a second-grade math teacher.
To be honest i’m not sure my imagination will be able to stretch that far. I’m all for people trying new things however I probably won’t be able to take her seriously after the years of popcorn fluff she has been in. If they give her glasses there is a chance she will only look hotter, so they are going to have to uglier her up. (Not that all smart people are ugly. Although, if you are both smart and attractive then good for you!)
I suspect it will be bad whatever they decide to do.