What metaphors are used in Meneseteung by Alice Munro?

The mysterious woman from Pearl Street, also known as the swamp angel, turns up at Almeda Roth's back door, and leads her to a breakthrough rather than a breakdown because the marginal world of Pearl Street, with its apogee of exclusion, the swamp that "No decent woman" would dare approach, is not periphery but alternate centre. Because of the symbolism of place in the story, this significantly unnamed woman may be seen, to use Catherine Ross's metaphor, as an emissary from the lower world, a world Almeda has been conditioned by the world of her father to abhor