Most of us have a pretty good understanding of the power of a mother’s love. Heaven knows we’ve seen it portrayed enough times on page, stage and screen. The majority of the time, we’re given a sense of not just the power, but the purity of that power. A mother’s love is meaningful and unconditional.

But when that love turns toxic, when it becomes all-consuming? That’s when we bear witness to the darkness, for there can be no light without shadow.

“Run,” the new movie from Hulu, offers us a look at that toxic darkness. Directed and co-written by Aneesh Chaganty, the talented filmmaker behind 2018’s excellent “Searching,” this is a chilling and emotionally charged dive into the circumstances of one mother’s love and how fear and delusion can twist that relationship into something dark and hurtful.

We’ve seen variations on the “mother from hell” formula before, but few have achieved this level of genuine scares. Sure, there are a couple of moments that threaten to teeter over the edge into camp – always a concern with these kinds of movies – but Chaganty’s steady hand and a pair of dynamite performances keep things on the rails. That barely-restrained sense of impending lunacy contributes greatly to what is ultimately a top-notch viewing experience.