Calcium can breach benzene's defenses: Calcium plays a major, multifaceted role in biology and mineralogy. In organic chemistry, though, it is largely overlooked and overshadowed by the carbon compounds of its cousins lithium and magnesium. Wilson et al. now report that the element was just biding its time: Several organocalcium compounds that they prepared can alkylate benzene by displacing a hydride, with no need for a more conventionally reactive leaving group such as chloride (see the Perspective by Mulvey). This surprising, previously elusive reaction attests to the unusual nucleophilicity of the carbons bound to calcium. Science , this issue p. 1168 ; see also p. 1132