Shiqi Zhang spent many months sitting alone in a dark room, staring intently into the lens of a confocal microscope as she focused a laser beam on plant cells mounted on a glass slide. She was measuring changes in the intensity of fluorescent light emitted by the cells when they were hit by a laser beam. The subtle, painstaking work was worthwhile: from the resulting colorful images, she was able to measure the amount of phosphate within individual living cells of a symbiotic plant-fungus system—something that had never been done before.