Sam is an astronaut who has spent almost three years on the moon mining to produce power back on earth. Now this isn't explained in depth, so don't expect a lot of science stuff to go on. It isn't like the movie THE MARTIAN with Matt Damon, trying to science the shit out of stuff, this is literally about a man who has been stuck on the moon and who may be going insane due to the loneliness. After an accident Sam discovers that GERTY has been keeping a secret from him, and something crazy happens which is not supposed to happen.
While I don't want to give too much away by telling what happens in this movie, I do think it is an interesting idea. What happens if you realize that you aren't who you thought you were? Does artificial life of any sort (AI, Robots, Clones) get any say on if they live or die, or how they live? Should they?
This was a somewhat slow movie, there is not a lot of action, as the audience only follows one man in his descent into possible madness. But it is a good premise and the ending was fabulous as it asks some of the questions that I was asking. I absolutely recommend this when you want something that is a thinker of a film.