BETTY Buckley hasn't starred in one of M Night Shyamalan's films in nearly a decade, but it's not for lack of trying. The Broadway star first worked with the director, best known for his psychological thrillers and horror films, in a supporting role in his 2008 film The Happening.
Now, finally, she's back on Shyamalan's call sheet, and gets much more screen time, in his new thriller Split.
"Night is a really joyous being, a very passionate guy. I call him the shiny person," Buckley tells Weekend.
"Every time I see him I'm always giving him a bad time, saying 'listen Night, all I want to do is work for you. I don't care if it's just a cameo'.
"He's so busy and has so many projects. I'm just like 'call me, Night'. I can't help myself."
Shyamalan reassembled his core team from The Visit, his wildly successful 2015 film, and returned to his independent filmmaking roots by financing the film.
James McAvoy stars as Kevin, a man with at least 23 different personalities, one of which compels him to abduct three teenage girls.
Buckley plays Kevin's psychologist Dr Fletcher, who has worked tirelessly to understand all of his personalities and help him to keep the dangerous ones in check. She also believes his two dozen alters may be the key to unlocking hidden potential in the human brain.
"Some people think people (with Dissociative Identity Disorder) are acting," Buckley says.
"I was very intrigued by the subject matter when I saw The Three Faces of Eve as a kid. Then in college I read Sybil. It's a response to pain and suffering and torture. The mind creates a persona that manages that and protects the part of the being that suffered.
"It's the psychologist's job to help this person merge their personalities to make them functional in the world, and help them reveal to themselves that original pain that caused these splits in the personality."
McAvoy is astonishing in the role, going back and forth between personalities confidently and convincingly.
He was so impressive during one particular scene that as soon as Shyamalan called cut the cast and crew burst into spontaneous applause.
"In that scene where he is going moment to moment from one character to the next to the next, is one of the hardest things I've ever seen an actor do," Buckley says.
"It was such a pleasure to work with him. He's so warm and down to earth, humble, spontaneous and generous.
"I was so pleased when I met him with how open he is as an actor. It's really about locking those eyes and keeping that connection; not all movie actors are like that.
"I couldn't do what we have done in the film without that connection and trust between us."
Split needs a supremely talented cast, perhaps more than other films, because it's so sparsely populated.
McAvoy, Buckley and Kevin's three captives - played by Anya Taylor-Joy, Haley Lu Richardson and Jessica Sula - comprise the film's five key characters.
"I saw the film for the first time in November at the AFI Film Festival in LA... I was so fascinated at how he (Night) had edited everything. It seemed very modern and sleek to me," Buckley says.
"His storytelling is so economical. He reveals so much with images and shots like all the great filmmakers know how to do. He let the visual image tell the story."