Marvel has released the final trailer to "The Avengers: Age of Ultron" in preparation for its May release.

The film is one of the most anticipated movies of the year and the latest trailer gives more details away.

Throughout the past few months, there has been speculation as to what Scarlet Witch and Quicksilver's roles will be in the film. Based on the latest trailer, Scarlet Witch and Quicksilver seem like they are allies of Ultron, at least at the beginning of the film. The preview starts with the two heroes approaching Ultron.

In another sequence, the Scarlet Witch uses her hex powers on the Black Widow. In the preview, Black Widow's eyes turn red which resembles the Hulk's eyes being red in the past trailer.

Scarlet Witch's powers are probably the reason that Black Widow is able to see the flashbacks from her younger self and most likely explain the sequences from the past trailer.

But the trailer does show the Scarlet Witch and Quicksilver as allies of the Avengers. From what it looks like, director Joss Whedon is basing a lot of the film on the comics. In the comics, the Scarlet Witch and Quicksilver first start as villains, most notably as part of their father Magneto's Brotherhood of Mutants opposing their heroic rivals the X-Men, before joining the Avengers. In a final clip from the trailer, the Avengers are joined by Scarlet Witch and Quicksilver as they stand back to back fighting off Ultron's drones.

The trailer also finally gives audiences a first look at the Android Avenger, The Vision. The android appears at the end of the trailer and his face has a glowing yellow headpiece and mechanical eyes that behave like the iris of a camera.

Another revealing part of the trailer was the development of Black Widow and Bruce Banner's relationship. In a quick clip, there is an intimate moment of the two sharing a moment in what could be one of Nick Fury's safe houses. In the first film, the two had an emotional connection when Widow tried to help contain the Hulk.

Perhaps Whedon will development that relationship and help shape the characters in an unpredictable way.

One other plot spoiler that the trailer seems to have given away is that Tony Stark, wearing an Iron Man gauntlet, grabs Loki's staff. According to speculation, the staff is an important element as it may have the Mind Stone, one of the six Infinity Stones coveted by Avengers and Guardians of the Galaxy supervillain Thanos, which will likely be a key to the third Avengers film. If Iron Man has the staff, this could be foreshadowing that Baron von Strucker will be defeated in the film. Baron von Strucker had the staff at the end of the "Captain America: The Winter Soldier" end credits sequence and used it to experiment on people.

If it sounds like a lot of plot twists and turns, that is because this film is loaded with them. Whedon himself called the film a nightmare because of the expanded cast.

"They're very disparate characters. The joy of the Avengers is they really don't belong in the same room. It's not like the X-Men, who are all tortured by the same thing and have similar costumes," he stated according to The Hollywood Reporter. "These guys are just all over the place. And so it's tough. Honestly, this is as tough as anything I've ever done, and I haven't worked this hard since I had three shows on the air."

"Avengers: Age of Ultron" is set to be released on May 1. The movie follows Tony Stark, who tries to jumpstart a dormant peacekeeping program and things go awry. As a result, it is up to the Avengers to stop the villainous Ultron from enacting his terrible plans. The movie stars Robert Downey Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, Hayley Atwell, James Spader, Tom Hiddleston, Idris Elba, Elizabeth Olsen, Aaron Taylor-Johnson, Samuel L. Jackson, Paul Bettany and Jeremy Renner.