Plankton are the invisible engines of life on Earth, producing much of the planet's oxygen and forming the foundation of the oceanic food chain. They are also incredibly diverse, with tens of thousands of species described so far, and many more waiting to be discovered. Among them, protists, tiny, single-celled organisms, stand out for their extraordinary diversity and evolutionary significance, yet for decades, scientists could study them only through genomic data, as reliable imaging methods were lacking.