Downey stars as the iconic British detective in the film franchise, while Law plays his famous sidekick, Dr. Watson. Both will reprise their roles in the threequel. No director is yet attached.

From a script by Chris Brancato, Sherlock Holmes 3 will hit theaters nine years after the first sequel, Sherlock Holmes: A Game of Shadows, debuted in December 2011 on its way to earning $545.4 million at the worldwide box office.

Sherlock Holmes, which was released Dec. 25, 2009, earned $524 million globally. Guy Ritchie directed the first two films.

The Christmas 2020 calendar is already crowded. James Cameron's long-awaited Avatar sequel is scheduled to open Dec. 18, followed by Sing 2 on Christmas Day.

Susan Downey, Joel Silver and Lionel Wigram are producing Sherlock Holmes 3.

