Earth's Mightiest Heroes and Marvel's First Family share some of their greatest adventures! First, it's the battle of the century - the Hulk vs. the Thing! And it'll take the combined forces of both teams to stop the destruction! Worlds collide again when Ultron-7 crashes Quicksilver and Crystal's wedding! And the Avengers and the Fantastic Four each have roles to play in cosmic encounters with Annihilus and the Skrulls! Then, on a break from the FF, Mr. Fantastic and the Invisible Woman actually join the Avengers for the Super-Nova saga! The New Avengers and the Fantastic Four face the Kree - but why are Hank Pym and the Mighty Avengers breaking into the Baxter Building?!