Amidst the chaos of a global viral outbreak, a colossal polar vortex looms, threatening to encase almost the entire planet in ice. Scientists uncover that survival from the freezing conditions is possible only within a narrow 100-mile temperate belt near the equator. A virologist, who possesses the sole remedy for the pandemic, faces a race against time to reach this safe haven within a day, as the fate of humanity hangs in the balance.