Sometimes it’s okay to be the guy who doesn’t quite get it. Todd Haynes’s May December is one of the best-reviewed movies of the year, cast by its admirers as the intimate, domestic, sexually charged complement to the big brawling epics we’ve received from the likes of Christopher Nolan and Martin Scorsese. Its portrait of an all-American tabloid scandal, the female teacher romancing the teenage male student, has inspired critics to reach for literature-department words like “interrogate” to describe what Haynes is doing, the blend of prurience, satire, and straight-up weirdness with which the story unfurls. And I get what they mean: At times, May December feels like it’s struggling with its own story the way a detective labors with a perp, trying to get the movie to crack and tell us what it’s all about.

Unfortunately, the detective loses and the perp wins: The film keeps its secrets to the end, and I walked away bemused, puzzled, disappointed.

The setup primes the audience for discomfort and disaster. In a sultry-looking Savannah, Natalie Portman’s TV star Elizabeth shows up to meet and shadow a wife and mother, Gracie (Julianne Moore), whose complex past is the basis for Elizabeth’s new indie-movie role. In that past Gracie charted the same infamous path as Mary Kay Letourneau, seducing a seventh-grader, Joe, when she herself was in her mid 30s, bearing his child while in custody as a sex offender, and then marrying him upon her release and his arrival at legal maturity. Now 20 years have passed and they have three children together, the younger two of whom are about to graduate high school the week that Elizabeth appears.

The façade is suburban normalcy: The couple owns a nice house by the beach, the adult Joe works as a radiology technician and raises monarch butterflies, Gracie is a seemingly successful baker and floral artist, they own Irish setters, everyone in town is supposedly nice to them. Except for the person who mails Gracie a box of excrement that arrives at the same time as Elizabeth — something that hasn’t happened in a while, they tell the actress, but clearly happens often enough to be routine.

From this introduction the movie follows Portman’s character as she simultaneously conducts a kind of private-eye-style investigation into Gracie’s past — meeting her ex-husband, her lawyer, her son by the ex-husband; insinuating herself into the strip-mall pet shop where the relationship was originally consummated — and engages in some unsettling doppelgänger behavior, beginning with physical imitation and accelerating, inevitably from the audience’s perspective, to a hurried seduction of the vulnerable and sympathetic Joe.

The investigation primes us to look for some clarifying psychological revelation about Gracie’s behavior or true nature, which the movie briefly dangles but then deliberately retracts. The imitation game primes us to expect some sort of domestic catastrophe, with Elizabeth’s performance instigating the collapse of the May-December marital illusion, like sudden ecological stress overwhelming a fragile butterfly habitat. But again, after giving us a dose of domestic combat through the sudden angst and doubts of Joe — himself the butterfly taken from his chrysalis too soon, get it? — the movie also pulls back, letting the marital conflict fizzle out somewhere off-screen, returning us to the Gracie–Elizabeth duality instead.

I think I do understand what the movie is showing us within that dynamic — that Elizabeth, whose background as a child of academics makes her desperate for artistic respect, isn’t actually half as good an actress as the scandalous woman she’s come to Savannah to try to understand. Everything that Portman and Moore do on-screen, together and apart, serves that revelation well. Portman is a good actress playing a mediocre actress, and her character’s strange behavior makes sense as an attempt to will herself into talent that she lacks. Moore is a great actress playing a great actress, whose performance is a gravity well for both her current family and, in an outer orbit, the people she’s betrayed.

Maybe the skill of their performances is enough to justify the movie. But if your story is all about a pair of actresses in a weird kind of competition with each other, in the end you want to get some clarity about what’s going on underneath the act. And in refusing both that kind of psychological revelation and the normal plot-driven satisfactions of a melodrama, May December seems just a little bit too infatuated with its own inscrutability. I was waiting to be horrified or shattered at the end, and instead I spent the last few minutes tuned out and musing over secondary questions — like, honestly, how can Joe and Gracie possibly afford that beachfront house?