Acclaimed indie filmmaker Hannah Fidell’s gripping feature-length effort, “A Teacher” (2013), was a career-making debut. Lodged somewhere between psychological thriller and character study—a portrait of a woman slowly unraveling— the drama centered on a Texas high school teacher (Lindsay Burdge) engaging in a sexual affair with her student. “A Teacher,” was evocatively ambiguous in its compelling ideas of desperation, the crucial things missing in our lives, and the way damaged people go to dangerous lengths to fill them. What made the film a bold standout— especially by 2020 standards, in retrospect— is the way the horribly misguided actions of the teacher are implicit and speak for themselves.