Since bursting onto the screen with his feature length debut - the superb, ultra-violent, profanity-strewn In Bruges (2008) - writer and director Martin McDonagh has established himself as one of the most exciting directors working today.

With his third film, Three Billboards Outside Ebbing, Missouri he has delivered a thrilling, powerful and darkly comic crime drama, arguably his finest work.

Set in the fictional town of Ebbing, the film sees bereaved mother Mildred Hayes (Frances McDormand) erect three billboards chastising the local police department – including the amiable, ailing chief Bill Willoughby (Woody Harrelson) and his volatile deputy Jason Dixon (Sam Rockwell) - for failing to catch her daughter’s killer.

As with his previous directorial outings, the real pleasure of McDonagh’s script and direction is his refusal to adhere to the typical dramatic beats of the genre with which he works, rendering all the more powerful the shocking twists and quietly devastating revelations that present themselves throughout.

At the heart of McDonagh’s film is a powerhouse performance by McDormand. The actress is spellbinding, perfectly capturing Mildred’s seething rage and unwavering determination to see justice done no matter the cost to those around her.

Rockwell is equally captivating as Dixon, whose bigoted infantilism masks a deeper, moving complexity.

Powered by two mesmeric central performances and McDonagh’s brutal, profane prose, Three Billboards Outside Ebbing, Missouri is an unflinching, heart-rending meditation on grief, violence and forgiveness. The must-see film of the year.