“There’s a bad spirit here,” we’re told in a new trailer for Jenna Cato Bass’ “Good Madam.” The South African horror pic sees Tsidi (Chumisa Cosa), a single mother, forced to move in with her estranged mother, Mavis (Nosipho Mtebe), a live-in domestic worker. Mavis cares for a mysterious, ailing white Madam. She agrees to let Tsidi and her young daughter (Kamvalethu Jonas Raziya) move in, but is quick to remind them about the rules of the house. “You can’t run, you can’t touch the fridge, you can’t go into the pool alone, and the most important thing, don’t ever go in madam’s room,” she emphasizes.

It’s not long before Tsidi becomes convinced that something sinister is going on inside the house. “It’s not that mama dislikes the house — the house doesn’t like mama,” she tells her daughter.

“All the films I work on come about when several things fall into place, or click in my head. In this case, I’d really been wanting to to explore the horror genre,” Bass told us. “For most of my life I’d been completely unable to watch scary movies: I was a sensitive child. At the same time, genre means nothing to me without substance — what it’s saying about our world. So I wanted to tell a story about a domestic worker who gets to reclaim her agency, along with the home she has lived and worked in her whole life. So using this particular genre was a way to provide a literal exorcism of our country’s trauma.”

Bass co-wrote “Rafiki,” Wanuri Kahiu’s 2018 romance about two women in Kenya. Her directing credits include “Flatland” and “High Fantasy.” The former was the opening film of the 2019 Berlinale Panorama.

“Good Madam” made its world premiere at the 2021 Toronto International Film Festival. You can catch it on Shudder starting July 14.