By the end of the year, physicists at the DESY laboratory in Germany may have caught a glimpse of an exotic dark-matter particle known as an axion. Andreas Ringwald and co-workers are planning an experiment at the lab’s FLASH free-electron laser, a device that generates extremely bright beams of high-frequency light by accelerating electrons. The researchers will try and create axions by passing the laser light through a vacuum in the presence of a magnetic field. If they succeed, it could help physicists understand dark matter, dark energy and even why matter exists in the universe at all.