Scientists discovered that diverse bacteriophages produce proteins that disable MurJ, an essential bacterial lipid II flippase, locking it in a single conformation and halting cell-wall synthesis. High-resolution imaging revealed how these viral proteins trap MurJ and trigger bacterial death, identifying a conserved vulnerability across multiple bacteria. The finding offers a new antimicrobial target that could inspire therapeutics operating through a non-traditional mechanism, potentially circumventing existing resistance pathways. Translating a viral protein mechanism into a drug will require work on delivery, stability, and specificity, but the discovery provides a concrete molecular entry point for antibiotic development.