I have just watched this movie so this is all fresh in my mind. The cast is a solid one and I particularly think that the young boy's role is well-played. This is an emotionally charged film or, at least, could be.
The story surrounds a pre-WW1 family unable to express love and affection to one another. Each member, from father, mother, and more centrally, the son are scared by the events of recent years. Enter a childless widow, as teacher, who gently draws the boy from his imaginary world.
The script has relatively few words expecting the direction and acting to provide the electricity. It just doesn't quite get there. There are scenes of lonesome characters crying as the lightning strikes over their rich mansion, but I am simply unconvinced by their presumable deep ingrained distress.