Though his “Avengers” film begins production in February, Robert Downey Jr. is still focused on getting his next “Sherlock Holmes” movie off the ground.

Sources tell Variety that Warner Bros., Village Roadshow and Team Downey have selected a writers’ room that includes “Guardians of the Galaxy” scribe Nicole Perlman, “Baywatch” scribe Justin Malen, “Rogue One” writer Gary Whitta, “Tomb Raider” Geneva Dworet-Robertson and “Snowden” screenwriter Kieran Fitzgerald to help shape the script and story for next installment.

The previous two films both brought in more than $500 million worldwide. The threequel has always been a priority for the studio but Downey’s schedule has been busy considering his commitment to playing Tony Stark (Iron Man) in the Marvel universe.

Downey is attached to star and Jude Law, who played Watson in the previous pics, is also expected to return. Guy Ritchie, who directed the first two films, is expected to return to direct.

Susan Downey, Dan Lin, Joel Silver and Lionel Wigram are attached to produce.

The writers room concept first commonly used in TV, has become a trend more studios are using for films, especially when it comes to shaping universes. Paramount set one up for “Transformers” and Universal is doing something similar with their classic monster universes.

This is a rare case in which a room is being set up for just one film. However one source said that in this case it makes sense to gather a good group, rather than have several writers rewrite or polish, which happens to films often in the development process.

Perlman is not only is penning Marvel’s first female superhero film “Captain Marvel” but is also on board to write the “Pokemon” movie “Detective Pikachu” for Legendary. Malen already has a history with the studio having recently written the comedy “Bastards” for WB and also has “Office Christmas Party” which opens in December. Besides “Rogue One”, Whitta has a handful of pics in development including “The War Magician” with Benedict Cumberbatch. Fitzgerald is currently working on “Cascade” for Fox.

Dworet-Robertson has also written “Dungeons and Dragons” for Warner Bros. as well.