Last month, Marvel’s Doctor Strange added the always fantastic Chiwetel Ejiofor (Secret in Their Eyes) to an already terrific twosome consisting of Benedict Cumberbatch (The Imitation Game)—who plays the titular doctor—and Tilda Swinton (Trainwreck). And as much as it appeared likely that Marvel was going to continue to stockpile British talent for their film (a formula that usually works), sources say that the studio may have instead offered Canadian Rachel McAdams (Southpaw) the lead female role for the upcoming film.

Doctor Strange, which tells the story of the flamboyant Stephen Strange, who serves as Sorcerer Supreme and protector of Earth from mystical threats, is being directed by Scott Derrickson (Sinister 2). McAdams, who currently stars in HBO’s True Detective, had already rubbed shoulders with another eccentric doctor in 2009’s Sherlock Holmes. Highlighting the often incestuous nature of Hollywood, Holmes was played by Robert Downey Jr. (The Judge) in that film, a fellow alum of the Marvel Universe (as the incomparable Tony Stark). McAdams’ potential co-star in Doctor Strange, Benedict Cumberbatch, is perhaps best known for his role as the very same Sherlock Holmes in the BBC television series Sherlock.

Since nothing has yet been confirmed, there is no word on who McAdams is set to play, although some speculation has her playing Clea, a disciple and eventual love interest to Doctor Strange.

Written by Jon Spaihts (Passengers), Doctor Strange is slated for a November 4, 2016 release date.