On Christmas Eve, 1898, a young woman gives birth while caught outside in a swirling blizzard. Thaw follows the unsettled life of this child, as she grows into a disquieting presence in tranquil Cupboard Cove. Hazel Boone lives life on its border, moving among familiar strangers, her body driven by temptation and an inner fire. Her self-indulgence creates a shame that percolates down through generations, seizing everyone in its path including her son, the painter David Boone, and his young apprentice, Tilley Gover. Seventy years after her birth, during a winter of constriction, a tragedy repeats itself, and the residents of this small outport re-discover that passion can be as destructive as it is redeeming.