Helena Bonham Carter has joined the cast of Legendary Studios' film adaptation of the Enola Holmes books.

Written by Nancy Springer, the young adult novels spanned six volumes and follows Enola Holmes, the fourteen-year-old sister of established detective Sherlock Holmes.

Recently, it was announced that Stranger Things star, Millie Bobby Brown has been signed up to play Enola. Carter, 53, will portray Enola's mother in the project.

Jack Thorne has penned the film's script, which reportedly borrows characters and settings from the universe of Sherlock Holmes. The film is said to revolve around Enola, who calls upon her elder brother’s help after ascertaining that their mother has vanished. Enola’s sleuthing skills rival Sherlock’s and leads to her solving numerous missing person cases.

Besides Legendary, Brown and her sister, Paige Brown, are producing the film through their banner PCMA Productions.