The goal is to treat unborn children as early as possible, before their disease causes irreversible damage. But the ambition is to do so without heritable DNA changes, that is, by targeting only somatic tissues and avoiding sex cells. Fetal genome editing, then, differs from embryo editing, which has raised so much controversy in recent years. The best way to understand how far it has come and how much remains to be done is to tell the story of the scientist most committed to this challenge. The opportunity is provided by a longread published in STAT, where Tippi MacKenzie’s biography is interwoven with a review of the field.