I think the turning point for Ned occurs when he is trapped in the beach house while the storm hits. Prior to that he sees himself as this Greek god-like figure attempting this heroic feat. In terms of imagery, everything prior to this is associate with summer and the daytime. However, once the storm passes, Neddy seems to be weaker and more of a foolish figure. We learn more negative things about him from the conversations he has (they are broke, something has happened to his daughters, he tried to borrow money from friends, and so on). Plus the imagery is suddenly that of the fall and early evening, which represents his decline. Many critics have viewed this story in terms of the life cycle because of the imagery used by Cheever.