If you want to map the tiniest parts of a protein, you only have a few options: You can coax millions of individual protein molecules to align into crystals and analyze them using x-ray crystallography. Or you can flash-freeze copies of the protein and bombard them with electrons, a lower resolution method called cryo–electron microscopy (cryo-EM). Now, for the first time, scientists have sharpened cryo-EM’s resolution to the atomic level, allowing them to pinpoint the positions of individual atoms in a variety of proteins at a resolution that rivals x-ray crystallography’s.