Frances McDormand's face is one of the first things you see in "Three Billboards Outside Ebbing, Missouri," and it's impossible not to be struck by its pure decency.

Perhaps it's a result of all the other roles we've seen this uniquely fearless actress play, on stage and screen, wrapped into one. But you look at her face and you think: This person has a moral compass. Her side is the right one. We will be safe there.

That's the way it seems for a while in "Three Billboards," until suddenly it isn't so simple. It's a credit both to writer-director Martin McDonagh and to McDormand's revelatory performance that we don't see this coming nearly soon enough to steel ourselves.

McDormand plays Mildred Hayes, a mother who's suffered unimaginable loss: the rape, murder and incineration of her teen daughter. The film begins seven months later, as Hayes is driving down a little-used road near her home. She stops and stares at three dilapidated billboards.

She heads to the town advertising office and hands over a wad of cash. Soon, those billboards will be painted bright red and emblazoned with three messages: "Raped While Dying." ''And Still No Arrests?" ''How Come, Chief Willoughby?"

A grieving mother searching for answers from a lazy police force. What could be wrong with that? Our righteous anger intensifies as a self-satisfied priest comes to her home, sips tea in her kitchen and explains that she's out of line in going after the chief. Mildred lectures right back at the priest, telling him that he is complicit, as a member of the church, in church sex abuse. And then she tells him to get out of her kitchen.

She's only getting started. This, it turns out, will be Mildred's go-to stance: Fight back and fight harder, no matter how profane or even violent she needs to get.

So much for black and white.

"Three Billboards" is a veritable study in gray. Willoughby (an excellent Woody Harrelson) comes to visit Mildred, and he's a decent and caring guy. The billboards are plain unfair, he tells her — it's not easy to catch a killer. She suggests they test the DNA of every man in town — heck, in the country. He finally tells her he has terminal cancer. She says she already knew. And she adds: "They won't be as effective when you croak."

Mildred and the chief, at least, have a grudging respect for each other. The same can't be said for her relationship with Officer Dixon, a hapless, moronic, racist, dangerously temperamental and buffoonishly violent Mama's boy, played with complexity and finesse by Sam Rockwell in a constantly surprising performance.

Mildred's take-no-prisoners quest for justice will bring her into a fiery confrontation with Dixon. But there's no way you'll be able to foresee the twists and turns their relationship will take.

There are no clear heroes here, and no clear villains, and needless to say, one should not expect to take away any easy lessons, either.

Except perhaps this: There's no better time than right now for a high-profile movie led by a meaty, complicated female character — and no better actress than McDormand to take it on.

And you can put that on a billboard.


'THREE BILLBOARDS OUTSIDE EBBING, MISSOURI'

***½

STARRING: Frances McDormand, Sam Rockwell and Woody Harrelson 

DIRECTOR: Martin McDonagh 

NOW SHOWING: At The Grand 16 (Lafayette). 

RUNNING TIME: 1 hr., 55 mins. 

MPAA RATING: R (Restricted) Under 17 requires accompanying parent or adult guardian. 

WHY IS THIS MOVIE RATED R? For violence, language throughout, and some sexual references.

Excellent (****), Good (***), Fair (**), Poor (*)