One of the best movies I've seen in awhile.
Very tense and palpable, post apocalyptic wasteland irradiated from nuclear war. A valley untouched by the radiation is discovered by a civil engineer who starts to rebuild.
"Very slowly paced, very subdued and understated. About the nature of people and all the little things that drive our actions, like uncertainty and paranoia and loneliness."
The ending is what made me post this here. It floored me. Very ambiguous at first, but the more you think on it, the more you realize that the interpretation of things goes as follows:
John did not killed Caleb, he saved him once and save him again when Caleb tried to fall on purpose. He wanted to test how good John was, Caleb did a creepy smirk the second time John was trying to pull him and that means that he understand that John was trustworthy and more deserving than himself. They both moved the piano then Caleb left, he left because John convinced him that he wasn't good for Ann. John was heartbroken after Ann went out to find Caleb so he went to the fountain then jumped. Ann saw him and was sad from what happened (she pushed the glass from the table part). Last part was John's soul watching Ann playing the piano. John looked happy, Caleb unknown, Ann lonely for being alone again. This is how I see what happened.
https://www.reddit.com/r/movies/comments/3isopw/official_discussion_z_for_zachariah_spoilers/
Definitely worth watching...