The narrator begins to sketch the results of Amory's relationship with Eleanor by observing that neither of them would ever again have an adventure of the kind they shared. Beginning by explaining that Eleanor lived in Maryland with her grandfather, the narrator backtracks to the first time the two met.
In Maryland one day, Amory is walking through the country reciting Poe when a sudden storm forces him to rush through a field looking for shelter. In one of the haystacks he hears someone singing Verlaine, a French poet. Eleanor asks who is walking through the field, and Amory responds that he is Don Juan and climbs up beside her on her haystack.
The two share a literary and youthful conversation, and they discover that even their thoughts follow the same paths. They part in the rain with a kiss goodnight, and Amory feels himself quite enamored by the country and this eighteen-year-old girl, who has lived in France, who angered all her Baltimore relatives because of her wildness, and so came here to live with her grandfather. The two spend a great deal of time together, talking of their love and the seasons. Eleanor regrets the times she lives in--that she, who is quite intelligent, must marry a man who will be her intellectual inferior.
On the night before Amory is to leave, they ride horses out to a cliff. Amory predicts that on her deathbed, Eleanor will lose her paganism and call for a priest. In response, Eleanor gallops headlong toward the cliff, but throws herself off the horse just before it goes over the cliff. Their love spoiled after this event, Amory leaves for New York. The two exchange wistful and lovely poems several years later, in memory of their love.
In many ways, Amory's relationship with Eleanor seems to be far more substantial and equal than his relationship with Rosalind (though that may have been an impression formed by the dialogue form of the narrative presenting the other relationship). Amory and Eleanor share a love for literature, and both have personalities that defy convention, but the relationship fails. It fails partially because of the season, because of Amory's former heartbreak, and because of Eleanor's wild streak. The relationship begins in late summer, past love's prime, and, with the advent of autumn, must end. The sad timing and Amory's spent emotions disbar him from love. Finally, Eleanor is actually too unconventional for Amory. Like Clara, she is a strong, independent woman who is incapable of submitting herself to a man.
All of these factors contribute to her final semi-suicide attempt, which she resorts to as an act of desperation. While the women in the novel, and the time period it depicts, are becoming progressively more liberated, they are still relegated to marry. Eleanor rebels against this societal norm to some extent.