Could the next weapon against malaria come from a better understanding of biological clocks? A new study shows that malaria parasites sync their gene activity with the circadian rhythms of their host, like two pendulum clocks with synchronized swings. If scientists can identify the molecular signals behind this mysterious synchronicity, they might be able to develop new anti-malarial drugs that throw malaria’s internal clock out of step with its host, essentially “jet-lagging” the parasites.