Australian native Thomas M. Wright is no stranger to dark material. He portrayed a haunted ex-con in Jane Campion’s series “Top of the Lake,” wrote and directed fierce plays for his Black Lung theater company and examined a twisted relationship in his 2018 directorial debut, the black comedy “Acute Misfortune.” But few of his past projects approach the level of anguish and suspense in his sophomore feature, “The Stranger,” which plays in Un Certain Regard May 20. “I certainly grapple with difficult ideas and truths in my work,” Wright says. “But the world is a dark place.”

Though he directed plays for years, Wright felt he “didn’t have any right to do it” onscreen until he was cast in “Lake” by Campion. “At the end, I said to Jane, ‘I’m thinking of writing and directing,’ She said, ‘You need to learn to write first, and when you’ve written something, send me the third draft.’ She was a generous supporter of mine.” He credits her and directors like Garth Davis and Warwick Thornton for teaching him by studying their work on set.

Wright based “Stranger” on an infamous 2003 child murder investigation, and centered his fictionalized script on two duplicitous men (played by Joel Edgerton and Sean Harris) whose seemingly chance encounter sets the story in motion. “I wanted it to be like a dark room with a crack of light in the far corner,” he says. “Through the whole film, you’re walking toward that light.”

He met with Edgerton for a possible role in the 2018 drama “Boy Erased.” Though “Misfortune” took Wright out of the running, Edgerton asked to watch his finished film. “He immediately said, ‘Whatever you want to do, I’ll make myself available. Let’s find something to collaborate on,’” Wright recalls.

Edgerton, also a producer on “Stranger,” had optioned Kate Kyriacou’s book “The Sting: The Undercover Operation that Caught Daniel Morcombe’s Killer.” He felt Wright was the best choice to adapt it after seeing how he handled another complicated true story with “Misfortune,” but as the father of a young son, Wright had reservations. “One reason I chose not to show the child or family [in “The Stranger”] was to make a film with a clear moral perspective. I couldn’t presume to know anything of the experience of that family. But I could see that there was a story about empathy and making meaning in the wake of violence, not violence itself . . . All of the actors went very deep on this film. I think it left a mark on everybody.”

Despite his initial concerns, Wright ended up casting his then-8-year-old son Cormac (his child with his longtime partner, a ceramicist) as the son of Edgerton’s detective character. “There’s something unknowable that leads human beings to commit violence against one another,” he explains. “I needed to find my personal response to that idea, and in order to do that, I needed to make it personal. That’s my stake in this film.” Additionally, “I wanted to [include] something that put the viewer at the center of an experience like that.”

Wright, who’s repped by UTA and Stacey Tetro Intl., is open to taking on more acting roles. And while he’s not quite comfortable with helming episodic television, his main goal is to write and direct features like the ‘40s and ‘50s films he still watches, and get them released theatrically.

“I have an idea for a very difficult, realistic, more political, dark Australian film, but I don’t think I’m quite ready for that one yet,” he laughs. “I’m interested in taking on forms of mainstream traditional cinema and trying to make them feel personal and new again.”