Yes dark, but that reflects the personality of some of the characters. Times were tough. Making a living there was tough. A very male dominated society where one would have repressed any emotions particularly those of a feminine nature. At first you loathe the main protagonist but in the end you feel compassion for him and his unfulfilled self.
A film to see again,but only after the first viewing is fully digested. Benedict Cumberbatch is brilliant in this