A dark-matter experiment deep in the Soudan mine of Minnesota now has detected a seasonal signal variation similar to one an Italian experiment has been reporting for more than a decade. The new seasonal variation, is exactly what theoreticians had predicted if dark matter turned out to be what physicists call weakly interacting massive particles (WIMPs). WIMPS might have caused the signal variation, but it also might be a random fluctuation, a false reading sparked by the experimental apparatus itself or even some exotic new phenomenon in atomic physics.