A Teacher (2013)

 A high school English teacher (Lindsey Burge) becomes increasingly obsessed with the student (Will Brittain) she is having an affair with. The film is done largely sans backstory (though some things are implied), and without any internal monologe, or even intimations of the same. So we only know what we see, we can observe the teachers gradual mental unwinding, but we never learn the reasons behind it. It's a kind of story telling some will find frustrating, but here, for me, it really worked. The kid is good, but it's Burge's very committed performance that makes this a engaging watch. ***