In his presentation, Sebastian Hasenstab-Riedel, speaker of the CRC 1349 “Fluorine-Specific Interactions,” not only traced the path from fluorspar to toothpaste, but also sought to contextualize the ongoing debate over a ban on PFAS from a chemical perspective. At NatLab, the focus was particularly on the role of fluorinated materials in fuel cells as energy sources for modern propulsion systems, for example. And in the large experimental lecture shortly before midnight—which, as always, served as the grand finale of the Long Night at the Institute of Chemistry and Biochemistry—the audience was shown, among other things, just how reactive fluorine can be by “igniting” a brick.