Mathematician Marcus du Sautoy sets out to find the hidden code behind the natural world, across three episodes covering numbers, shapes, and prediction. The first traces number patterns from seashell spirals to galaxy structures, arguing that the same ratios recur at every scale. The second starts at the Giant's Causeway in Northern Ireland and moves through bee honeycombs and salt crystals to the less obvious geometry behind mountains, clouds, and trees. The third turns to forecasting, opening with lunar eclipses as a solved prediction problem before testing how far the code can go: du Sautoy examines the actual behavior of lemmings against the popular myth, looks at methods used to catch serial killers, and works through the reasoning behind the specific number 1.15 as an alternative to Douglas Adams's 42. Du Sautoy narrates and demonstrates most of the mathematics on camera, using physical objects and locations rather than abstract equations to make each pattern visible.