Greenland is shedding roughly 275 billion gallons of meltwater every 40 hours, and this film follows glaciologists trying to measure exactly how much of that is being driven by ocean heat rather than air temperature alone. Field teams drill and analyze ice cores dating back 400,000 years, reading the trapped air bubbles for a direct record linking CO2 concentration to past temperature swings. The camera goes onto the Antarctic ice sheet to show how warmer water reaching the underside of glaciers is thinning them from below, a process harder to see than surface melt but potentially more consequential for sea level. Researchers explain albedo itself: how bright ice reflects sunlight back to space, and how each patch of open water or bare rock that replaces it absorbs more heat and accelerates the next round of melting. The film moves between core-drilling sites, ship-based ocean measurements, and interviews with the scientists doing the work, building a picture of a feedback loop already underway rather than a future projection.