A very high Chern number Topologically nontrivial electronic structure can often be characterized by the Chern number, the value of which is related to the magnitude of some of the exotic effects predicted to occur in such systems. Many topological phases discovered so far have a Chern number of 1 or 2, but higher values are also theoretically possible. Schröter et al. predicted that the chiral material palladium gallium (PdGa) would have a Chern number of 4, and they confirmed that prediction using photoemission experiments. Interestingly, the sign of the Chern number was opposite for the two enantiomers of PdGa. Science , this issue p. 179