The Avengers are ready for battle against any enemy who dares attack Earth! In this action-packed pop-up book, see your favorite super-heroes leap off the page. The Avengers have assembled to fight a new evil threatening mankind-the robotic menace known as Ultron. Learn how Iron Man, Captain America, Thor, the Hulk, Hawkeye, and Black Widow became a team and find out what special skills each brings to the ultimate group of heroes - the Avengers!