The earth has experienced a cycle of ice ages and warmer interglacial periods for thousands of years, but recent scientific research suggests that our climate is far less stable than previously thought. By analyzing ice cores from Greenland and other locations, scientists have discovered that the climate can shift abruptly, potentially triggering a massive freeze that could devastate modern society. This documentary explores the potential for a future big freeze, examining the role of volcanic eruptions and ocean currents in shaping our planet's climate and the potential consequences of a sudden, dramatic shift in global temperatures.