Avengers 2 Movie Plot Spoilers, Latest News: Synopsis Released, Marvel Reveals New Avengers' Nemesis

Marvel has broken its silence on the upcoming Avengers sequel, "Avengers: Age of Ultron," by releasing the official plot synopsis of the film.

The synopsis reads: "When Tony Stark tries to jumpstart a dormant peacekeeping program, things go awry and Earth's Mightiest Heroes, including Iron Man, Captain America, Thor, The Incredible Hulk, Black Widow and Hawkeye, are put to the ultimate test as the fate of the planet hangs in the balance. As the villainous Ultron emerges, it is up to The Avengers to stop him from enacting his terrible plans, and soon uneasy alliances and unexpected action pave the way for an epic and unique global adventure."

Although the synopsis provides very little details on the movie, it confirms rumors on how the villanous Ultron came to being.

With S.H.I.E.L.D. destroyed, the Avengers need a stop-gap mechanism to confront the diabolical threats facing mankind. Stark attempts to revive a sleeping giant, Ultron, who is described as a self-aware, self-teaching, artificial intelligence.

However, Stark's plan backfires as the revived Ultron decides that humans are the world's main enemy and have to be destroyed.

Thus, the Avengers -- Iron Man, Captain America, Thor, the Hulk, Black Widow and Hawkeye -- are once again reunited to save the world.

"Avengers: Age of Ultron" is the epic follow-up to the biggest Super Hero movie of all time. Released in 2012, the first Avengers movie raked in more than $1.5 billion in the box office worldwide.

The sequel is expected to repeat or even surpass the original film's success. "Avengers: Age of Ultron" is scheduled for release on May 1, 2015 in North America, in 2D and IMAX 3D.

Robert Downey, Jr. will return as Iron Man to lead the superheroes' fight against Ultron. Joining him are Chis Evans (Captain America), Chris Hemsworth (Thor), Mark Ruffalo (The Hulk), Scarlett Johansson (Black Widow) and Jeremy Renner (Hawkeye). Another actor reprising his role is Samuel L. Jackson as Nick Fury.

Playing the part of Ultron is James Spader whom Downey and writer-director Joss Whedon described as the best choice for the role. "Spader was my first and only choice. He's got that hypnotic voice that can be eerily calm and compelling, but he's also very human and humorous. He's the guy to break The Avengers into pieces," said Whedon in a Screen Rant report.

Other new characters appearing in the upcoming Avengers sequel include Scarlet Witch, to be played by Elizabeth Olsen; and Baron Wolfgang von Strucker, to be played by Thomas Kretschmann.

Scarlet Witch appeared at the end of "Captain America: The Winter Soldier" where she was seen making some blocks float on air.

The Baron was also seen at the end of "The Winter Soldier" while he held Scarlet Witch and Quicksilver captive. He was seen holding Loki's staff, the same device that enabled Loki to control Hawkeye's mind in the first Avengers movie.

Paul Bettany will play the part of The Vision, a character created by Ultron with the power to manipulate his density.

Meanwhile, Downey hinted in a recent interview that Iron Man would be a casualty in Avengers 2. Asked on the possibility of an Iron Man 4, Downey replied, "There isn't one in the pipe," sparking speculation of Iron Man's demise in Avengers 2.