'Avatar 2' release date, cast news: Stephen Lang takes lead after James Cameron fires Sam Worthington and Zoe Saldana

"Avatar" is the highest-grossing film of all time. At the directorial helm was James Cameron, the same director who supervised the filming of another super box office hit "Titanic." As the anticipation for the epic sci-fi movie's sequel builds up, the production is reportedly undergoing a major casting shake-up with Cameron firing "Avatar" protagonists Sam Worthington who played the disabled marine Jake Sully and Zoe Saldana who assumed the character of Neytiri, a Na'vi.

With the original movie's main characters being staved off from production, reports across rumor land suggest that Stephen Lang (Colonel Miles Quaritch in the movie) will now take the lead as the sequel's new protagonist. This may sound like a significant departure from Col. Quaritch's villainous role in the first movie where he headed the security arm of a large enterprise operation to mine unobtanium, a highly valuable mineral found on Pandora.

The speculations over Lang's new lead role in "Avatar 2" was apparently triggered when Cameron mentioned about Quaritch's character transformation throughout the epic trilogy. "His character will evolve into really unexpected places across the arc of our new three-film saga," said the famed director in a Deadline exclusive reveal.

Col. Quaritch's appearance and his supposed evolution in "Avatar 2" are quite odd as he was killed and presumed dead in the previous film. But a number of reports indicate that Cameron will inject surprising twists to the storyline, MNR Daily reported. In addition, Sigourney Weaver will reportedly reprise the role of Dr. Grace Augustine. It can be recalled that the exobiologist died in the original film after the Na'vi people failed to transfer her soul to her avatar from her dying body.

Meanwhile, the official release date remains unconfirmed although it is expected to hit the big screen in 2018.