In 2004, a 64-year-old woman in Indiana had a catheter put in to help with dialysis. Soon after the procedure, she came to a local hospital with low blood pressure and what turned out to be a dangerous antibiotic-resistant infection from a bacteria called Enterococcus faecalis. Today, that woman’s blood samples helped solve a long-standing mystery: how this deadly bacteria neutralizes the most powerful antibiotic used to fight it.