MARUM researchers Ursula Röhl and Alex Wülbers head out to sea to read Earth's climate history in the layers of sediment sitting on the ocean floor. The film follows their work aboard a research vessel, showing how sediment cores are drilled, hauled up, and split open to reveal bands of material laid down over thousands of years. Röhl and Wülbers explain what these layers can tell scientists about past temperature swings, ocean circulation, and ice ages, treating the seabed as an archive that predates any written record. Shipboard labs, coring equipment, and close shots of the extracted cores give a concrete sense of how this kind of fieldwork actually happens, rather than just describing the findings in the abstract. As part of a short-form series on deep-sea science, this entry keeps its focus narrow and technical, staying with the two researchers and their specific project rather than widening into a general climate lecture. It is a compact look at how physical evidence from the ocean floor gets turned into a record of the planet's past.