This booklet looks at Rabbi Abraham Joshua Heschel's little-known involvement in discussions with Vatican II. Heschel drafted the third official memorandum that the American Jewish Committee (AJC) submitted to the Vatican on the relationship between Christianity and the Jews. Titled "On Improving Catholic-Jewish Relations," this paper, instead of dwelling on the past, presented the basis for a way forward. As the work of Vatican II wore on, Rabbi Heschel and AJC remained deeply involved in the development of the groundbreaking statement Nostra Aetate, which changed deeply the relationship between the Church and the Jews. Even as this relationship continues to evolve and the understanding of the meaning of Nostra Aetate continues to unfold, the distinct imprint of Rabbi Heschel can still be felt.