Every week, somewhere on our planet, people die in a flood. We can now predict many types of floods well before any rain has even fallen, or the storm has even begun to form. We have spent billions of Euros setting up sophisticated flood prediction systems that undertake billions of calculations to predict when and where floodwaters will be. But what is the point of all of this if nobody can understand the danger that they are in, or imagine their homes and lives swept away? The floods in Germany in the summer of 2021 showed failures to prevent deaths. But was this a failure of science, or a failure of imagination? This lecture will take you on a river journey, fol-lowing the paths of individual water droplets, immersing you in both the scientific and human experience of flood disasters.