The final scenes

Would anyone have an explanation for the tragic incident at the end of the film? It was so abrupt and there seemed to be no satisfying follow up. Also, I assume that José went back to Buenos Aires to live with Mercedes. It is interesting that he should be involved with the woman who was his mother's college friend and also his father's lover. The collection of characters seems like a writhing nest of slimy snakes. If that was the director's intent, then I must congratulate her for succeeding so brilliantly.