The ocean is the most consistent motif in the novel. Mary’s narrative begins with an explanation of her mother and her great-great-great-great-grandmother’s connections to the ocean, and these details establish the sea as a symbol of Mary’s curiosity about the past and about the generations who lived before the Return. Likewise, Mary’s complex feelings about God are also expressed in terms of the ocean when she describes her doubts about the reality of a huge body of water ruined by salt. Throughout the novel, Mary remains determined to experience this phenomenon for herself, and because her heart and mind are so consumed by her fervent fixation, her behavior causes separations and divides in her relationships with Cass, Travis, and Harry. Ultimately, she does find the ocean, but not without making grievous sacrifices along the way.

On a deeper, more allegorical level, the ocean represents the linked ideas of cleansing and sanctity, contrasting with the Forest’s allegorical symbolism as a ruined place that has been polluted and overrun by Unconsecrated. Significantly, the unnamed man whom Mary meets on the beach helps her to understand the timeless, unceasing action of the tides that rise and fall to sweep away the decaying undead. As he states, “The beach will be what it always is. Just a beach” (305). Grateful for her newfound freedom, Mary’s decision to swim in the ocean represents a deeper cleansing that merely washing away the soot and mud of the paths, for she also rids herself of the fears and limitations that the Forest represent. The ocean thus proves to be the great liberator that Mary hoped for, and it stands as the strongest symbol of The Persistence of Hope amidst Death.