Looking for magnetic clues Thin films of the neodymium nickelate NdNiO ₂ doped with strontium have recently been found to be superconducting. This materials class bears structural and electronic similarities to the famed cuprate superconductors, but how far the analogy goes remains unclear. Lu et al. used resonant inelastic x-ray scattering to look for magnetism, which exists in the cuprates, in Nd _1-x Sr _x NiO ₂ films (see the Perspective by Benckiser). The authors observed magnetic modes in the undoped compound that had a doping evolution consistent with the behavior of a doped Mott insulator. Science , abd7726, this issue p. 213 ; see also abi6855, p. 157