Sue, Reed, Ben and Johnny are four young men preparing for a mission in space. They are astronauts and they know that experience is going to change their lives, but they do not suspect how much.
In space they will receive an enormous amount of radiation. Radiation can kill you, but in the case of these astronauts it does not. They do not die, but their bodies undergo physical changes that make them people with special abilities.
In this way, they use their new abilities to become the Fantastic Four, the abilities of which we have spoken before to do good to Humanity, being a kind of superheroes.
The four are coming together because the Earth is in danger. An old friend of the Fantastic Four has become their enemy, so our planet is in danger, being the only ones who can do something so that our world does not disappear.