During cell division in a mother cell, the 23 chromosomes that carry the human genome must be first copied and later delivered to two newly forming daughter cells. At least in healthy cells, the result is astonishingly flawless, and no chromosome is ever lost. Not so in malignant cells, where rampant chromosome segregation errors generate a continuous flux of new genetic variants that support metastatic growth and resistance to chemotherapy. A multilayered protein structure called the kinetochore executes the chromosome delivery program. In a highly interdisciplinary collaborative tour-de-force, the groups of Andrea Musacchio and Stefan Raunser at the Max Planck Institute of Molecular Physiology studied the outermost layer of this structure, the kinetochore corona. With the help of single particle cryo electron microscopy and protein reconstitution they revealed the structural organization of the corona's main building block, the RZZ complex, and deciphered the mechanism of corona assembly. Their results illuminate the molecular foundations of genome inheritance through the generations.