While the character's name is Jig, Hemingway, as narrator, does not refer to her by name; instead, he uses "the girl" in contrast to "the man" or "the American" for the male character. This use of "the girl" establishes the tone of the male character's speech to her: patronizing and inconsiderate.
Jig does not, at first, realize that her lover is so patronizing and self-centered. However, as the conversation between them develops, she begins to discern his selfishness in asking her to have an abortion. At any rate, she realizes that the relationship between them will never be the same regardless of her decision:
'Then what will we do afterward?'
'We'll be fine afterward. Just like we were before.'
'What makes you think so?'
'That's the only thing that bothers us. It's the only thing that' made us unhappy.'
This last line of the man's is key to Jig's understanding of his true character, for it indicates his selfishness. As she walks to the end of the station, the girl gazes at the other side, the fertile side where there are fields of grain and trees with a river beyond. With the wisdom of intuition, she realizes that they have relinquished the fertile side and remain on the barren one.
Knowing that things can never be as they have been, even though her lover insists that they can, Jig now negates everything that he says. When he asks her repeatedly to "come back," Jig knows there is no going back. She knows they will remain on the barren side of the tracks in their life together.