A pretty good indication that a movie's going to be good, or at least interesting: directed and co-written by Shane Black.
It is set in the funkiness and moral rot of mid-70s Los Angeles. In the opening scene, that kid from Iron Man 3 swipes one of his dad's porn mags (for our younger audience: a magazine with pictures of naked women; how retro) and is perusing a picture of one "Misty Mountains". When, unexpectedly, a small car plummets off the nearby freeway, crashing entirely through the young man's house. When he checks out the wreckage, the dying victim is … Misty Mountains, herself, posed just like in the mag, except for a lot more blood.
An ultra-Dickensian coincidence, to be sure, although one Dickens might not have come up with himself. Whatever. We're off to concentrate on our protagonists: Healy (Russell Crowe), whose profession is beating up people for money. And March (Ryan Gosling), a widowed sad-sack semi-sleazy private eye, way too fond of booze and cigarettes, bringing up a precocious 14-year-old daughter on his own.
March is not above taking clients' money for worthless cases, namely investigating whether Misty is still alive. He and Healy are drawn together when Healy is hired to dissuade him from even a bumbling investigation. Gradually, they become aware that a lot of people involved in shooting Misty's final porn movie are turning up dead.
Amid all the carnage, there's a lot of hilarity. According to IMDB, this was originally going to be a TV series. (And it's slightly reminiscent of the series The Good Guys.)