Professor Ruti Teitel, author of Humanity's Law, is perhaps best known for her foundational work on the concept of transitional justice. She is a proven norm entrepreneur. Her development of the concept of transitional justice demonstrates her ability to detect progress for those victimized by atrocities. It also demonstrates her skill in developing responses to those atrocities. Transitional justice, as Teitel envisioned it, has an ambitious agenda as a ‘conception of justice associated with periods of political change, characterized by legal responses to confront the wrongdoings of repressive predecessor regimes’. That said, transitional justice in its original conception has a specific focus, limited by time and circumstance. Those limits are in part responsible for its success as a concept and practice.