SPOILER ALERT: the following article contains massive spoilers, including the ending. If you have not yet seen the movie, proceed at your own risk, or better, come back to this article later!
SPOILERS AHEAD
The Mole Agent Plot Summary and Synopsis
An 83-year-old man poses as a resident in a Chilean nursing home to see if he can find signs of abuse.
Source: Wikipedia (CC BY-SA 3.0).