Lena Pernas is challenging the conventional view of the role of mitochondria during infection. Her work has shown that mitochondria counteract invading pathogens, rather than being simply hijacked or damaged by them. Going forward, her team aims to uncover how organelles sense and respond to infections, and how metabolism and organellar function are rewired to defend against pathogens at different organizational and temporal scales. Her findings have the potential to reveal new aspects of organellar biology and broaden our understanding of the role of human metabolism in the progression of infectious disease.