It's not the titular "Three Billboards Outside Ebbing, Missouri" that cause a monumental fuss in that imaginary small town, it's what's unexpectedly written on them.
Blank for years, hugging a bend in the road like lonely sentinels doggedly doing their duty, they send a blistering message in enormous black letters on a 20-foot-high background of the brightest red:
"Raped While Dying"
"And Still No Arrests?"
"How Come, Chief Willoughby?"
In the hands of uncommon writer-director Martin McDonagh and a splendid cast toplined by Frances McDormand in what could be the role of her rich and varied career, the how and why of those billboards becomes a savage film, even a dangerous one, the blackest take-no-prisoners farce in quite some time.
Bleak humor notwithstanding, "Three Billboards," concerned as it is with grief, revenge, the nature of violence and the pervasiveness of despair, has serious issues on its mind. But if you're expecting anything close to pious moralizing, you are very much in the wrong place.
If Martin McDonagh's name means something, either from plays like "The Lieutenant of Inishmore" and "The Pillowman" or unhinged movies like "In Bruges" (which got him an Oscar nomination), you know that audacious is a tepid word for work that delights in saying the unsayable and doing the unthinkable.
But no matter what you know, you won't be completely prepared for this energetically demented production that removes the footing from under our expectations with unnerving consistency. Don't think of outguessing the turns taken, just keeping track of them is hard enough.
It is character, however, not plot, that's at the heart of the proceedings. With collaborators like McDormand and costars Woody Harrelson and Sam Rockwell, McDonagh presents a film full of individuals who are so intensely imagined, and finely written, that they are simultaneously more extreme and more nuanced than we will be expecting.
In its verve, its flair and its precision, it's McDonagh's writing that makes all that possible, and using actors who often have worked with him before and directing his own work ensures there will be no slip-ups.
"By the time one of my scripts goes into production, I've been sitting with it for seven years, and every one of those lines is carefully chosen," McDonagh told Moviemaker Magazine. "If you signed on to do my script, you're doing my script, and that's the end of it."
Getting all the best lines as the film's furious and ferocious prime mover, the woman who put the billboards up and doesn't care who knows it, is grieving mother Mildred Hayes.
Played with convincing and uncompromising fierceness by McDormand, Hayes has been almost literally driven mad by her daughter Angela's unimaginably brutal death several months earlier as well as the local police's inability to come up with a suspect.
A terror both holy and unholy, a hardcore obsessive and unapologetic about it, Hayes pays for the billboards not so much with any specific purpose but because her daughter's fate has so taken over her mind that she can't think about anything else, not even what all this is doing to her son, Robbie (Lucas Hedges).
In a more conventional film, the police chief called out in those billboards would be Villain No. 1, but Harrelson's Chief Bill Willoughby, starched uniform and all, might be the most sane and reasonable person in the entire movie.
Not only does he have reasons why no suspects have been found, not only is he a fine husband and father (Abbie Cornish plays his wife), but he has a serious problem of his own to deal with.
This is not to say that all members of Ebbing's police force are men of similar mettle. Oh no. Look no further than Dixon, the chief's right hand (McDonagh veteran Sam Rockwell), to find an officer who is a racist hothead and small-minded momma's boy as well as an unswerving advocate of police brutality.
Also irritating Hayes, as it turns out, is that her ex-husband, Charlie (John Hawkes), is living with a barely legal girlfriend (Samara Weaving) who is so dense she can't even get mad at her.
A woman of Hayes' fortitude is not necessarily going to be devoid of an admirer of her own, but in a backwater like Ebbing that turns out to be James (a deadpan Peter Dinklage), who says of himself, "I know I'm a midget who sells used cars and has a drinking problem, I know that."
"Three Billboards" takes so many devious turns that it just about whipsaws our expectations, but it's always laser-focused, always clear where it is going and in its determination to take us there with it.
Because nothing is out of bounds where McDonogh's work is concerned, there are moments, as its characters wrestle with anger and the consequences of anguish, when you may fear we'll be left with no one to side with, but a director this smart has got that covered as well. Just not in the way you have in mind.
'Three Billboards Outside Ebbing, Missouri'
Rating: R for violence, language throughout, and some sexual references
Running time: 1 hour, 55 minutes
Playing: ArcLight, Hollywood, Landmark, West Los Angeles