ET has a first look behind the scenes of the upcoming Suicide Squad, featuring Will Smith, Jared Leto and Margot Robbie.

In the movie, some of the world's most notorious supervillains are recruited by the government to execute dangerous black ops missions in exchange for clemency. What makes it different from other comic book movies is that there are, in fact, no good guys.

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Characters include Deadshot (played by Smith), the world's deadliest and most accurate marksman, Joker (played by Leto), Batman's arch nemesis, Harley Quinn (played by Robbie), the Joker's psychotic sidekick and lover, and more.

"There's a part of [Deadshot] that is thinking, 'Maybe I might have made a wrong turn or two in [my] life,'" Smith says in a behind-the-scenes clip.

All of the actors seemed to find something human about their characters, no matter how diabolical, to sympathize with and latch onto.

"I didn't realize that the Joker was 75 years old -- the story of the Joker," Leto says. "I never thought in a million years that I would have the chance to play a role like this."

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Robbie appreciated the chance to play a strong female character in a blockbuster action movie.

"Dr. Harleene Quinzell is who Harley Quinn was before she became Harley Quinn," says Robbie. "She was working at Arkham Asylum and that's where she met Joker and fell for Joker and then born out of that was the transformation into Harley Quinn."

The film seems to be the perfect movie for anyone who tends to root for the bad guy, but it also works for the more traditional moviegoer, who longs for good to triumph over evil.

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"We sort of landed on the separation between being a bad guy and being evil," Smith says. "It's not a movie about good versus evil, it's a movie about bad versus evil."

Suicide Squad opens Aug. 5.