The Witch and Split star Anya Taylor-Joy and Game of Thrones' Maisie Williams are already signed up for the ensemble young-adult superhero movie being directed by Josh Boone.

Dawson will play Dr. Cecilia Reyes, a medical doctor who has the ability to generate a protective bio-field around herself. The character assumes a mentor role for the group of fledgling heroes. (Last year, speculation surfaced that James McAvoy would return as mentor Professor X and that Alexandra Shipp would return as mentor figure Storm, but those characters are not in the script, according to sources, and the actors are not slated to appear in the movie.)

Taylor-Joy is playing Illyana Rasputin, code-named Magik, a girl who has learned sorcery and uses teleportation discs to travel. Williams is Rahne Sinclair, aka Wolfsbane, a girl struggling to reconcile her religious beliefs with her power to turn into a wolf.

The X-Men spinoff will focus on the angst-driven adventures of a diverse group of teens dealing with their newfound powers.

The movie is headed toward an early July start with a script by Boone and his writing partner, Knate Lee. Simon Kinberg and Karen Rosenfelt are producing. New Mutants has a release date of April 13, 2018.

Dawson already plays a nurse in Netflix's Marvel shows and has been one of the threads connecting the shows. She has appeared in Daredevil, Luke Cage and Iron First and will reprise her role in The Defenders, which Netflix will release August 18.

The actress is coming off starring opposite Katherine Heigl in the Warner Bros. thriller Unforgettable and also voiced Batgirl in The Lego Batman Movie.

She is repped by CAA.