Not only as an explosive but also in its sometimes surprising reactions, tetraazidomethane proves to be an exciting substance. As shown in the cover picture, the compound can be synthesized from commercially available trichloroacetonitrile in one step, isolated by preparative gas chromatography as a limpid liquid, and characterized by its 15N NMR spectrum measured with natural isotopic abundance. Although a simple trapping product is formed in the presence of cyclooctyne, tetraazidomethane undergoes a more complex transformation with norbornene. Further reactions are described by K. Banert et al. in their Communication on page 1168 ff.