It's winter. A nameless engineer is in Starkfield, Massachusetts on business and he first sees Ethan Frome at the post office. Ethan is a man in his early fifties who is obviously strong, and obviously crippled. The man becomes fascinated with Ethan and wants to know his story. When Ethan begins giving him occasional rides to the train station, the two men strike up a friendship. One night when the weather is particularly bad, Ethan invites the man to stay at his house. In the hall the man hears a woman talking angrily, on and on. When Ethan speaks, the voice stops. The man tells us that he learned something that night which allowed him to imagine Ethan's story. Now we go back in time 24 years and learn about Ethan's life.
Ethan has walked from his farm and sawmill into town to pick up Mattie Silver from the church dance. He peeks in the windows of the church basement and sees Mattie dancing with Denis Eady and is jealous. Mattie is Ethan's wife's cousin. Her parents both died just over a year ago, and she was left with nothing. Her father had apparently swindled some of the relatives out of their savings, so nobody wanted to help Mattie. Zeena, Ethan's wife, is always sick, and decided to let Mattie live with them in exchange for doing the housework and helping the ailing Zeena.
Ethan liked Mattie from the beginning and worried that Zeena was too hard on her. The two women soon adjusted to each other (sort of) and things weren't as bad as they could have been. Meanwhile, Ethan has fallen in love with Mattie and wants to spend all his time with her.
Mattie soon comes out of the dance, and Ethan watches while Denis Eady tries to give her a ride home. She brushes him off and then Ethan reveals his presence. Ethan and Mattie are happy to see each other. They discuss possibly doing some sledding in the future. Neither is afraid to sled down the hill – at the bottom of which lies the deadly elm tree. The walk home is altogether lovely and romantic, but when they arrive, the house key isn't under the mat like it usually is.
Soon, Zeena, looking ill and scary, comes downstairs and lets them in. She's usually in bed by this hour but she couldn't sleep. She is obviously suspicious of their behavior. The next day she announces that she will be gone overnight visiting a new doctor. Mattie and Ethan make good use of her absence and enjoy a romantic dinner for two. Unfortunately, the cat breaks Zeena's favorite dish and Ethan isn't able to locate any glue until after Zeena gets back. The first thing Zeena does when she gets home is to tell Ethan that she's kicking out Mattie. He protests, but fighting is useless. Then Zeena finds the broken pickle dish and is super upset (it had been a wedding gift).
Ethan decides he'll run away with Mattie, but then a combination of lack of cash and guilt stop him. Still, he insists on driving Mattie to the train station. He takes her on the long route, so they can look at different places they enjoyed together. By the time they get to the town sledding hill, it's already dark. As they are contemplating sledding, and pondering the hopelessness of their situation, Mattie suggests that they sled into the elm tree and kill themselves. Ethan agrees and they smash into the tree. But they survive.
Then the story goes back to the present and we find the engineer right where we left him, about to enter the Frome kitchen. When he does enter he learns that the woman who was talking on and on in an argumentative tone is…Mattie! She has spinal disease and can't move without assistance. Zeena is there too, cooking. They all three live together, an unhappy family in the Frome house.