When Loki returns from the void wielding the power of the Tesseract, he forms an uneasy alliance with the resurrected Red Skull to conquer Earth. Nick Fury activates the Avengers Initiative, bringing together Earth’s mightiest heroes — but clashing egos, past grudges, and dangerous secrets threaten to tear the team apart. As the Chitauri army descends on New York, the Avengers must unite, not only to save the world, but to prove that they can work as one.