Karisa Karango arrives to visit his grandmother Nyanya under strange circumstances in “The Letter,” lured back to Mombasa in Kenya where the family has long held a much coveted piece of land. It was a Facebook post from his Uncle Steve that convinced Karango to return, though when the two meet face-to-face, Steve says he’s never been on social media, having no knowledge of the claim he supposedly made that Nyanya has been killing children and suspects her of witchcraft. Still, he allows that he heard things when a herdsman came to the farm to work with the cows and felt as if he was being strangled without anyone laying a hand on him.

“I just don’t understand, it sounds like a movie,” Karango says to Steve, losing sight of the fact he’s already in one, and by that point in Maia Lekow and Christopher King’s transfixing documentary, you’ve probably lost yourself in it as well when the co-directors have expertly lured you into the drama in Kilifi County where there’s been a sudden rash of elder deaths tied to suspicion that they have been engaged in the dark arts. While centuries’ old beliefs die hard among some in the community, Lekow and King find that it’s actually a relatively new trend that’s fanning the flames as a scheme to scare people off the land that they’ve spent a lifetime to cultivate has become popular and it’s spread to Nyanya’s farm where there’s a particularly valuable maize crop.

However, the threat is even more insidious than intimidating Facebook posts and letters to Nyanya when Karango comes to learn that it may be linked to relatives living on his grandmother’s property and “The Letter” becomes a fascinating portrait of those who selectively draw on history for inspiration without having any respect for it, as Lekow and King make clear in charting Nyanya’s extraordinary conservatorship of the land that she was passed down from her father. As the film beautifully illustrates, this was hardly a guaranteed inheritance, essentially compensation for giving up on her future to take care of her sister’s kids after she took ill, making the notion that she’ll have the life she made after stolen away from her once more unbearable to consider, and although Karango offers a way into the story for Lekow and King, he starts to recede into the background as Nyanya contemplates going through with a cleansing ceremony known as oathing that would satisfy some but at odds with her Christian faith.

The power of belief, in ways both good and bad, is made tangible in “The Letter,” and for every bit an unconvincing case is made for Nyanya practicing witchcraft, she has clearly created a place of enchantment where Lekow and King ease one in for a story that could easily become a part of the local lore for generations to come, albeit not needing the embellishment that happens over the years to keep it interesting. In spite of the role of technology in proliferating false information as far as its subject is concerned, the use of it to bring this story to the world certainly has its benefits.

“The Letter” does not yet have U.S. distribution.