by alejandroariera â€œThere is a thin line that separates laughter and pain, comedy and tragedy, humor and hurt,â€? wrote American humorist Erma Bombeck. Irish playwright and filmmaker Martin McDonagh (â€œIn Bruges,â€? â€œSeven Psychopathsâ€?) obliterates that line with his darkly funny and tragically sad third film, â€œThree Billboards Outside Ebbing, Missouri,â€? the story of a woman who has yet to overcome stage two of grief â€”angerâ€” after the brutal rape and murder of her daughter.