An unnamed Narrator, an engineer assigned to a job at a power plant in Corbury Junction, Massachusetts, describes his first impressions of Ethan Frome. Frome is a badly crippled but still striking older man whom the Narrator has seen at the post office in Starkfield, the town where he is staying. Harmon Gow, a former stagecoach driver who knows the histories of all the Starkfield families, responds to the Narrator's questions about Frome by telling him that Frome was disfigured in a "smash-up," an accident that occurred 24 years ago. But Gow provides few details.
The "frame story," told in the first-person by the Narrator builds suspense around Ethan Frome and the events leading to the "smash-up" that disfigured him. By telling the story through the device of the "frame," so that the Narrator is trying to learn a story that has already happened, Wharton gives Ethan's story a sense of inevitability.
A strike at the power plant extends the Narrator's stay in Starkfield through the winter. The Narrator observes the effect of the harsh climate on the psychology of the town's inhabitants, and compares their situation to that of an army under siege. He thinks about Gow's comment that Ethan has "been in Starkfield too many winters."
The Narrator hopes to learn more about Ethan's story from his landlady, Mrs. Ned Hale (formerly Ruth Varnum), but she is strangely reluctant to speak of the accident. Gow relates that the accident happened in front of her childhood home, and that she had been a close friend of the victims.
Mrs. Hale's distressed reaction to the Narrator's inquiries adds to the suspense about what happened to Ethan.
When the local livery stable owner Denis Eady's horses fall ill from an epidemic, Gow suggests that the Narrator hire Ethan to drive him to the train station and back every day. Gow explains that the Fromes are desperately poor, and that their farm has poor soil and an obsolete mill. In addition, Ethan has been plagued with "sickness and trouble"—his father was kicked in the head by a horse, resulting in disability, insanity, and death; his mother also went insane; and Ethan's wife Zenobia (also called Zeena) suffers from frequent real or imagined illnesses.
Although Ethan says little as he drives the Narrator to the station, the Narrator learns that Ethan is interested in engineering, and lends him a book on popular science. To the Narrator, Ethan seems a tragic hero, "frozen" in silence, who's inner need for knowledge and learning contrasts with his outwardly simple life. The Narrator realizes that he and Ethan have more in common than he expected.
One day, a severe winter storm blocks the railroad. Ethan drives the Narrator the full ten miles to the power station, along a road that passes by the Frome farm. Ethan tells the Narrator that the coming of the railroad resulted in less traffic along the road to the farm, and relates that Ethan's mother died of loneliness and insanity as a consequence of the Fromes' isolation.
Even the railroad bends to the whims of nature in this region. Technological progress has not improved life for the Fromes, instead causing them to become even more isolated. The Frome women, who do domestic work at home, are forced into even deeper isolation than the men.
On the way home the storm worsens and Ethan and the Narrator are forced to take shelter at the Frome farm. As they enter the house, the Narrator hears a woman's complaining voice, but cannot make out her words. The narrator says that he then discovered the "clue" to Ethan Frome that allowed him to "put together this vision of his story."
The narrator does not reveal the "clue" until the end of the novel, injecting even more suspense into the novel. At this point, the reader is left to assume that the whining voice belongs to Ethan's sickly wife, Zeena.