One of the things I loved about this novel is how Ethan Frome's frustration is never fulfilled. That is the tragedy; that whatever happiness he believes is possible is never realized. In youth he wants to be an engineer, an aspiration that is put on hold when he has to take care of the family farm. When his parents die, he marries the woman who came to help him take care of the household, Zenobia. She proves to be a hypochondriac with real and imagined health issues that tie Frome to the home, unable to leave the small village as he tries to hold the farm together and provide for a wife who is no longer loving or lovable.
But this is all the back story. When his wife invites her cousin, Mattie, to come live with them, to help around the house, Ethan is once again given reason to hope. Mattie's youthfulness, her vigor, bring an energy into the home and into Ethan's heart he thought was long dead. However, the reader knows that Ethan never leaves the village, that something tragic is on his horizon, for our first image of Ethan Frome himself is his limping through the snow, bent and broken.
My disappointment in the BBC production was rooted in the moment when the screenwriter allowed Ethan from to consummate his passion with Mattie. This was a sharp departure from the novel, an emotionally unworthy choice, because the tragedy of the novel is not that he does inevitably become trapped in his life but that he never knows any fulfillment. I suppose some might see his one brief taste of happiness being experienced and then taken from him in the climactic tragedy as somehow even more grievous. I clearly did not and would have preferred if the script had been more faithful to the novel.