The carbon–oxygen (C=O) double bond is an important chemical motif, particularly in compounds called ketones. Chemists expect that substituting the carbon for a heavier atom would produce 'heavy ketones', which are attractive targets to further understanding of chemical bonding and for synthesizing novel molecules. Now, Kohei Tamao at the RIKEN Advanced Science Institute in Wako, Japan, and colleagues have—for the first time—isolated a heavy ketone, where the carbon is replaced by germanium.