The Avengers 2

Following set-ups in Iron Man 3, Thor: The Dark World, and Captain America: The Winter Soldier, Earth's mightiest heroes reunite to save the world from Thanos, its deadliest threat yet.

As far as the tenuous relationships between the Avengers go, the sequel's director and scriptwriter Joss Whedon says, "it is the beginning of something complex and difficult." Cameos from other Marvel characters such as War Machine may also be in the cards. There are even stories circulating that Ms. Marvel may be introduced to the team! Whedon has teased that his script for The Avengers 2 contains 'two of my favorite characters from the comic book, a brother/sister act' - those who guessed that this meant Quicksilver and The Scarlet Witch were spot on. Sources have confirmed that both characters will appear, though studio execs have stressed that since Whedon is still in the process of drafting and re-drafting the film, anything could happen.