Convinced she has solved the prophecy, Isla crosses snowy Moon Isle with Oro shortly before dawn. Oro is excited enough to acknowledge that Isla may have found what he could not, even placing his crown over hers. As they walk, Isla thinks less about gaining power and more about saving Celeste, Terra, and the people she loves.

Isla asks Oro what he will do if the curses are broken, and Oro says he wants to rebuild Lightlark as a united realm rather than restore Sunling dominance. Oro suggests Isla might stay on Lightlark, but Isla privately knows her imagined future lies elsewhere. Isla then tells Oro about finding Azul’s ring with Celeste and suspecting Azul of poisoning her, though Oro insists there must be another explanation.

The dark-blue bird appears again, and Isla follows it through Moon Isle toward the ice mountains and a tree near the oracles. Remembering that the heart is near where darkness meets light, Isla and Oro take shelter in an ice cave and wait for dawn while watching the bird’s nest. During the wait, Moon Isle violently shakes, and Oro suffers with the island as it crumbles; when Oro asks Isla to sing, Isla sings a Wildling song until Oro’s pain eases.

At dawn, an egg beneath the nest falls and cracks. Its golden yolk rises with the sun, revealing that the heart of Lightlark has returned not as a plant, as Oro expected, but as an egg representing moon and sun. Oro joyfully tells Isla to claim it, and Isla feels triumphant because she has solved the riddle and may finally save her people and those she loves.

When Isla grasps the heart, its power floods through her, but an arrow suddenly pierces her chest. Vinderland attackers have followed them seeking revenge, and Oro burns them instantly, but daylight prevents Oro from leaving the cave to heal Isla. Dying and still clutching the heart, Isla summons Grim with her necklace; as Grim takes Isla away, Isla drops the heart and sees Oro’s devastated face before darkness claims her.

Afterward, Isla understands that the heart had been keeping her alive. Without it, Isla falls through a strange, star-filled in-between place and thinks of her dead parents, realizing that death is neither quiet nor quick.