Marvel Cinematic Universe is gearing up for Phase 3, which kick-starts with captain America Civil War and will continue beyond Avengers Infinity War Part I and Part II. While the third part of the Avengers series will premiere in 2018, the filming and script updates about the same have emerged.

Joe and Anthony Russo, who are directing the movie, have revealed that the filming will start from November. Infinity War is one of the most important Marvel movies because it not only has the Avengers but also other mighty superheroes from outer earth, who will join forces to fight the mad titan Thanos (who is trying to collect the Infinity stones).

As both the movies will be shot back-to-back, the multi-script writing too is in progress. While speaking with Collider, Joe Russo explained that considering they needed the script before filming begins in November, they have already started working on it.

"We had to. We start shooting in November, two movies back to back. So we need two scripts ASAP, and we probably started working on them six months ago." Anthony Russo said adding that Christopher Markus and Stephen McFeely are currently busy writing the story.

"As soon as we got into post [production] on this movie, we gave ourselves a few weeks to transition and then we spent half days with the writers, and a half in the editing room, for months. We'll get the first draft of both scripts when this movie opens."

Anthony and Joe Russo
The Russo brothers are set to helm both parts in the upcoming Avengers: Infinity Wars saga Anthony Harvey/Getty Images

As of now, the Avengers are holding their ground on earth during their fight with the super alien powers, but with Infinity War, the war will transcend to a cosmic level. The Russo Brothers, however, have clarified that they will keep the action sequences close to the rules of physics and will have plenty of "real world influence".

"We still have rules where we want everything to be based in physics in some way, or departing from our universe, or going to somewhere fantastical that the rules are very clear to the audience about how physics operates in that space," director Joe explained.

"So we're using a lot of real world influences for our cosmic approach and while you can't bring a level of 'realism' because a lot of things that you're dealing with in that space are theoretical, what you can do is bring a psychological realism to it and the characters can have a psychology that is relatable in a human storytelling level."

Avengers: Infinity War Part I is scheduled to release on 4 May 2018 and Part II is to be released on 3 May 2019.