What Roberts has just done, in an action that he and people who support him have performed hundreds of times, is to return to a practice that was abandoned more than 40 years ago. He has sampled the environment, hoping to find in the dirtiest, most germ-filled places an answer to one of the most pressing problems of our day. ... Drug resistance—the ability of bacteria to defend themselves against the compounds we use to kill them—has impaired the effectiveness of almost every antibiotic produced since the first ones were developed, in the 1940s. At least 700,000 people are estimated to die worldwide every year from infections that no longer respond to antibiotics. That toll could balloon to more than 10 million a year by 2050 if we can’t slow the spread of resistance or find new drugs; routine surgeries and minor injuries will become life-threatening. ... Yet making the necessary changes to stave off this catastrophe seems to be beyond us. We continue to take antibiotics with abandon (nearly a third of antibiotic prescriptions in the U.S. aren’t actually needed) and feed huge quantities of them to farm animals. And pharmaceutical companies—daunted by how quickly resistance can undermine drugs that may take a decade and a billion dollars to develop—are not rushing to fill the gap. ... He launched his campaign, called Swab and Send, in February 2015. For £5, participants got a sample tube, a mailing envelope, and an explanation of what Roberts wanted them to look for: a spot in the environment where bacteria were likely to be competing for nutrition and room to reproduce. He asked them to use their imagination. The less sanitary, the better.