Robert convinces the party to go to the beach. The women walk with their husbands, and Edna wonders why Robert doesn’t join her; he hasn’t been spending as much time with her as usual. Edna had never been able to swim, and Robert had tried all summer to teach her; but she was always strangely afraid of the water. Tonight, though, she swims confidently for the first time, and it brings her great joy and relief. The water seems infinite, and she feels a newfound strength. When she reaches shore again, she leaves the party and starts toward home.
We never learn why Edna had been afraid of swimming, but we can infer that it has something to do with the ocean’s infiniteness and opaqueness. The ocean is a place that is at once dangerous and completely free, a place where a person loses various kinds of gravity—the gravity of the limbs, the gravity of the social order. It has often been compared to the soul. Edna, now, plunges into the ocean like she plunges into her own formerly remote self.
Robert joins her; Edna describes her overwhelming response to the music and her estrangement from the people around her. She settles into a hammock near her cottage, though the hammock is not very clean. Robert brings her a blanket and sits by her side in pregnant silence. He leaves quietly as the other guests return from the beach.