The beginning of life is shrouded in mystery. While the intricate dynamics of mitosis are well-studied in the so-called somatic cells—the cells that have a specialized function, like skin and muscle cells—they remain elusive in the first cells of our bodies, the embryonic cells. Embryonic mitosis is notoriously difficult to study in vertebrates, as live functional analyses and imaging of experimental embryos are technically limited, which makes it hard to track cells during embryogenesis.