In a recent study conducted by Hongri Gong and colleagues, a respiratory supercomplex was isolated from the bacterium Mycobacterium smegmatis, and its structure was visualized at a resolution of 3.5 Å using cryo-electron microscopy (cryo-EM). The bacterium is a close relative to M. tuberculosis and a popular model used to study many other bacterial species. The detailed structure revealed how electrons were transferred in the cell in a process hitherto unseen.