More questions than answers (spoilers)
1. Who shot Mark, and why?
2. What is Alex's job?
3. What is the link between Mark and the doctor?
4. What is Robert's relation to Vera and to Alex? Initially I thought it was the third brother, but it is clear only Mark and Alex are brothers.
5. What did Vera write on the back of her pregnancy test? We do not know but it seems the crux of the matter, it would explain a lot we cannot now understand.
6. What has happened to Robert at the end? Alex was in Robert's house, then is seen driving away. Robert is not seen anymore.
7. Is Vera mentally unbalanced? I think she is. If not, I can understand even less of how the people in this film behave.