See this for the amazing cast, especially Christopher Plummer

Rating: 8/10 (18 December 2019)

First off, the cast --- wow. Daniel Craig, Chris Evans, Jamie Lee Curtis, Michael Shannon, Don Johnson, Toni Collette, Ana de Armas, Katherine Langford, and that absolute treasure of screen and stage Christopher Plummer. In a single movie of normal run time it's impossible to give all these accomplished actors enough individual screen time, but every one of them plays their part to virtual perfection as various members of a dysfunctional (but rich) family under the thumb of patriach Harlan Thrombey (Plummer). His apparent murder sets off a chain of infighting and personal back-and-forth among his children, grandchildren, and their spouses that has the feel of just one more round of backbiting that they have carried on their whole lives.
Everybody is excellent, but even in this cast Plummer stands out even though most of his appearances (as flashbacks) are restricted to the first half. He can dominate a scene just by being in it, and his delivery of lines is so effortless and commanding at a level that none of the others can quite reach. He's now age 90, so personally I'm saddened that we're likely not to see too much more of him. Enjoy.
The two major parts are de Armas, Harlan's live-in nurse (and the only genuinely likeable person in the cast, so we have no trouble rooting for her), and Craig, as the detective aiming to solve the case. A lot of the superficial look-and-feel of the story is supposed to resemble an Agatha Christie mystery, obviously, and the script has a meta touch in that old Thrombey has made his fortune as a mystery writer. But it very quickly veers off into eccentric directions that make this whole thing quite distinctive. There are loads of details that make for a constant thread of understated humor: e.g. the detective is "Benoit Blanc", an obvious callback to Hercule Poirot, but he has a thick southern-US accent that verges on parody. No one quite knows why he's there in the first place, he seems to be rather a bumbling fool, but this is something of a disguise too ... no spoilers! All the action takes place in a classic crumbling mansion complete with secret passages, side stairs, escape ladders -- and there's a sunroom with a throne-like chair surrounded by knives that resembles the Game of Thrones throne, and even has a key part to play at the end. And of course there's creepy Great-Nana Wanetta (K Callan) who sits by a stairway window all day (and maybe night, we can never tell) and says nothing ("How old is she??" "Nobody really knows.") Without giving anything away I'll just say that things wind up pretty much the way they rightfully should.
Knives Out is thoroughly fun and a great addition to the mystery movie genre.