At the end of the month, "Batman v Superman: Dawn of Justice" will throttle the DC Cinematic Universe into high gear, with Batman, Superman and Wonder Woman set to star in several additional films, including the two-part "Justice League" blockbuster. Chris Terrio, the Oscar Award winning writer of "Argo," will help bring the DCCU to life with director Zack Snyder, and he promises the tone of the films will only get lighter from "Batman v Superman" on.

"I initially thought I wasn't the guy to do 'Justice League' and went off to work on something else. But the first day I went to the set, I saw Jesse [Eisenberg] in a scene with Holly Hunter and I really did feel like I was watching some strange, great performance in an independent film," he told Wall Street Journal.

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"At that moment, I thought, 'I'm not done with this yet. I want to go back and keep telling the story,'" he continued. "'Batman v Superman' is a bit of an 'Empire Strikes Back' or 'Two Towers' or any similar middle film in a trilogy. The middle film tends to be the darkest one. I do think from 'Man of Steel' through 'Justice League,' it is one saga really."

"I expect 'Justice League' will be tonally not quite as dark as 'Batman v Superman,'" he explained. "From that point of view, I felt compelled to go back and try to lift us and myself into a different tonal place because I think when you write a darker film, sometimes you want to redeem it all a bit.

However, while he'll be in integral part of "Justice League Part One," he may not return for "Part Two." "I have written 'Justice League Part One,' but I won't necessarily write 'Part Two,'" he revealed. "This has been the most rigorous intellectual exercise I've had in my writing life. For 'Batman v Superman,' I wanted to really dig into everything from ideas about American power to the structure of revenge tragedies to the huge canon of DC Comics to Amazon mythology. For 'Justice League,' I could be reading in the same day about red- and blueshifts in physics, Diodorus of Sicily and his account of the war between Amazons and Atlanteans, or deep-sea biology and what kind of life plausibly might be in the Mariana Trench."

Due to start filming in in April, "Justice League Part One" is scheduled to open on November 17, 2017, though Ben Affleck, Henry Cavill and Gal Gadot will first be seen as Batman, Superman and Wonder Woman in "Batman v Superman: Dawn of Justice" on March 25, 2016.