Beneath the legend of the unicorn horn lies a structure more wondrous than myth: the narwhal's tusk, decoded at last by an international team wielding the most powerful X-ray instruments on Earth. Published in Nature, the discovery reveals a double-spiral architecture—opposing twists in the outer and inner layers—that gives this two-meter tooth its extraordinary strength across an animal's eighty-year life. The finding invites us to consider how nature encodes resilience not in brute mass, but in elegant, opposing tensions—and how one creature's tooth may yet teach us to build better, and to r