At breakfast, Dominic confronts Rowan for frightening Orly with blunt talk about fire, starvation, and the world’s collapse. Rowan apologizes when she learns Orly woke screaming, but she also defends telling him the truth because she believes children should be prepared for what is coming. The argument pulls Rowan back into her own memories of losing her home to fire, and it sharpens her resolve to accompany Dominic and Orly south to the seed bank so she can look for clues about Hank and understand what his life on Shearwater had become.

The journey south is physically hard but emotionally revealing. Rowan’s healing wound and growing stamina let her keep up, while Orly enthusiastically teaches her about the island’s plants and birds, showing her a richness she had not previously seen. The strange wind unsettles Rowan, but the tension breaks when Dominic and Orly bring her to South Beach, where vast colonies of penguins and seals transform the island from forbidding wilderness into a place of noisy abundance and wonder.

At the tunnel leading into the seed vault, Rowan sees that stormwater is still flowing inside, already threatening the facility. In the freezing vault, Dominic and Orly check the temperature, follow Hank’s list, and begin moving selected species into travel cases, revealing the scale and urgency of the work Hank left behind. Seeing Hank’s handwriting and the shelves of seeds makes Rowan understand the crushing burden he carried: deciding what biodiversity to save and what to abandon in a failing world. When Rowan notices moisture damage and concrete decay in the vault wall, she realizes the structure itself may not last much longer.

At the blue field hut where Hank once stayed, Rowan hopes for some trace of her husband but finds the room empty and stripped of anything personal. She notices the hut smells strongly of bleach and later learns that a third hut was recently swallowed by the sea, a story Dominic and Orly answer with a glance that suggests more is being withheld. That night, Orly tells a grisly island legend about the Shearwater Carver, and afterward Dominic admits that Orly believes the voices of slaughtered animals live in the wind. Dominic says he hears only one voice: his dead wife’s. Rowan is moved by the depth of his grief and attachment, and alone in bed she finds herself imagining Dominic rather than Hank, then recoils in shame from what that desire implies.

Rowan concludes that the trip has produced no concrete evidence about Hank, yet it has made one possibility harder to dismiss: Hank may have chosen to leave her. A flashback to one of their recurring arguments reveals a deep fracture in their marriage, as Hank wanted children and Rowan believed bringing a child into a ruined future was unethical and unbearable; his anger made her realize he did not truly understand her. On the brutal trek back through freezing weather and dense fog, Rowan is shaken by the sense of being followed, then reaches the lighthouse to hear violin music drifting through the mist. Dominic is moved to tears because his son is playing again, and watching him listen makes Rowan newly aware of the immense familial love and devotion she once believed she could live without.