The same virus that silently accompanies a mosquito through its entire life can devastate a human body within days — and the answer to why lies deep inside the cell, in the ancient organelles that generate life's energy. Researchers studying orthoflaviviruses such as dengue and Zika have found that these pathogens do not simply attack their hosts uniformly, but instead reshape mitochondrial structure and metabolism in fundamentally opposite ways depending on the host they inhabit. In humans, this rewiring leads to fragmentation, oxidative damage, and cell death; in mosquitoes, it enables quiet