At least, eventually: THR reports, building off of rumors that have been kicking around for a few months now, that Gerwig might actually start her two-film project by adapting The Magician’s Nephew, technically the sixth book of C.S. Lewis’ series, but which serves as a prequel to the rest. (Including introducing Jadis as a late-story antagonist.)
Mackey and Gerwig previously worked together on Barbie, where she played Barbie. (That’s a joke, in so far as most of the characters in Gerwig’s blockbuster are Barbie; Mackey played the Barbie who’s a Nobel Prize-winning physicist.) She joins a fairly small sorority of past White Witch performers, including Barbara Kellerman, who played the character in a much-seen BBC miniseries adaptation from the 1980s, and Tilda Swinton, who created a particularly martial version of the character for Disney’s 2005 film. In addition to Sex Education, Mackey’s other recent credits include a starring role in Emily Brontë historical drama Emily.
Worth noting that Netflix hasn’t confirmed this, or any other, casting for the movie yet: Meryl Streep is supposedly in talks to take on the role of Aslan, but the whole thing is still being kept in hypotheticals at present. The film is currently aimed at a November 2026 release date, complete with a brief IMAX theatrical run that Gerwig managed to “Hi, I just made a billion dollars with a Barbie movie” out of Netflix.