Based on a series of novels by author Nancy Springer, Brown will play Enola Holmes, who just happens to be the much younger sister of famed detective Sherlock Holmes (indeed, the character is 14, the age Brown will turn next month).
No release date has been announced for The Enola Holmes Mysteries, but you can catch Millie Bobby Brown as Eleven in Netflix's Stranger Things. Per Deadline, Brown will also produce through her company PCMA Productions.
The book series began with the 2006 title The Case of the Missing Marquess.
The novels feature several characters that Sherlock fans will be familiar with, including Enola and Sherlock's brother Mycroft, and Sherlock's partner Dr Watson. Millie has previously starred in the movie "Godzilla: King of Monsters", which was also bankrolled by Legendary Entertainment.
There is now no indication of when filming for The Enola Holmes Mysteries will begin or when the film series is due to hit our screens. Still, we're very happy to see Brown take on a new leading role and we'll definitely be keeping our eyes out for this one.