Scientists are fond of saying negative results are just as important as positive results, but after several decades of not finding something, researchers can be forgiven for feeling impatient. Back in the 1990s, experiments began trying to detect the particles that make up dark matter, the ubiquitous yet untouchable invisible material that apparently fills the cosmos. Since then, physicists have found more and more evidence that dark matter is real but not a single sign of the stuff itself. A new version of the long-running XENON experiment that started up late last year aims to finally break that pattern.