The movie is about Agnes (Kelly Macdonald), a stay-at-home wife and mother and church goer in upper New York (which is interesting as Macdonald's native accent is strongly Scottish - but she sounds mostly American here). She discovers a love of jigsaw puzzles, which leads her to Robert (Irrfan Khan), who becomes her partner in solving puzzles.
I wasn't particularly enchanted with the 20 minutes of setup to show what a boring life she has, and how unappreciated she is. It's necessary, but could have been better. Both Macdonald and Khan are good actors, but when they're on screen together the movie crackles. This is partly because whoever wrote it did a much better job when the two of them are together, but also because of the quality of the acting and the chemistry they have.
It's a quiet movie about a woman discovering that her very limited life can be expanded. I can't give it an unreserved recommendation, but it certainly has its moments.