The author’s cycle by Viktor Troitsky addresses the alphabet as a system of signs, where letters become keys to representations of the order of the world. The starting point will be Albrecht Dürer’s "Melancholia I" and the famous monogram AD. Through it, the conversation will lead to a broader range of questions: why the outlines of signs can preserve cultural memory, how geometry helps read symbols, and how alphabetical systems of different eras connected writing with the structure of the universe. This approach is particularly interesting for those who love art history, philosophy, visual culture, and intellectual narratives at the intersection of disciplines. Viktor Troitsky conducts an author’s cycle on world symbolism, examining it through forms - point, line, circle, cross, spiral, tree, labyrinth, and other images that have accompanied humanity for centuries. In this lecture, the focus shifts to letters: they cease to be neutral signs and become a reason for discussion about heritage, primary sources, cosmological images, and "mathematics for the humanities." Where to go in Moscow today is known by KudaGo.