A mysterious woman who washes up on the rocky coast of Shearwater Island during a violent storm, barely alive and guarding secrets about her past. As she recovers, she forms a tentative bond with the family who saved her, though she remains cautious about her true reasons for crossing the ocean.

The rugged, protective caretaker of the Shearwater Island research station and its precious seed bank. A widower, he raises his three children in isolation, teaching them to survive the harsh Antarctic climate while remaining deeply wary of outsiders.

Dominic's seventeen-year-old daughter is a wild and fierce teenager who feels more at home with the island's seal colony than with people. She acts as a bold protector of her family and the natural world, though she struggles with the limitations of their isolated life.

The eighteen-year-old eldest son is characterized by his sensitive nature, artistic soul, and talent as a violinist. He bears the weight of the family's past tragedies visibly and often serves as a gentle peacemaker within the family dynamic.

The nine-year-old youngest child possesses an encyclopedic knowledge of the seed vault and the island's operations. Intelligent and curious, he displays a maturity beyond his years and is eager to connect with the mysterious new arrival.