When Paul Tafforeau saw his first experimental scans of a COVID-19 victim's lung, he thought he had failed. A paleontologist by training, Tafforeau had been laboring with a team strewn across Europe for months to turn a particle accelerator in the French Alps into a revolutionary medical scanning tool. It was the end of May 2020, and scientists were anxious for a better view of the ways human organs were being ravaged by COVID-19. Tafforeau had been tasked with developing a technique that could make use of the powerful x-rays generated at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. He'd pushed boundaries on high-resolution x-rays of rock-hard fossils and desiccated mummies as an ESRF staff scientist. Now, he was dismayed by a lump of soft, squishy tissue.