James Balog spends years hauling time-lapse cameras onto glaciers across the Arctic, rigging them to shoot the ice every daylight hour so the retreat becomes visible instead of theoretical. The footage compresses months into seconds: a glacier face collapses into the sea, a valley of ice thins and darkens, meltwater carves channels that were not there the season before. Balog treats the cameras as instruments, not art, checking mounts and batteries in conditions that have already destroyed earlier rigs, while climate scientists work through what the accumulating images mean for sea-level forecasts. NOVA cuts between his fieldwork and researchers trying to put numbers on a process the pictures make undeniable. There is no reenactment here and little narration beyond what is needed to place a shot in time and location; the case is built almost entirely from what the cameras recorded, frame by frame, over years of return trips to the same ice.