David Lean used his wife, Ann Todd,
to great affect in this romance. The passion of Mary's life is Stephen (Trevor Howard) but she marries Howard (Claude Rains), a wealthy businessman who meets some of her needs. Their marriage is more of a contract than a union but both are satisfied until Stephen comes on the scene again. And then again.
It is hard to say why this movie works so well because little happens. It's success is shared by the acting of the three principals. The original novel was by H.G. Wells, hard to imagine that. I thought it was very good if you are in the mood for repressed and expressed longing and not much action.The ending works particularly well.