Today we have moved from the "end of history" to the "end of certainty." Everything moves at the pace of fluidity in an unstable orbit, constantly oscillating between transactional politics and confrontational polyphony. We live in the weakening of the "line" between peace and war, values and interests. The public good is at a disadvantage compared to individual prosperity, thereby enriching the power of the one, the strong, the ruler. Never has the world forgotten the ruler, who appears in different forms depending on the spacetime context he is given. We have entered the "uncharted planet Earth." The borders, the lines of the built and natural environment, the fixed lines in culture, as well as the lines of hospitality and communication in tourism, are in a confused state that requires analysis and attention. The form and shape that once bestowed beauty, harmony, and aesthetics to humans, as well as the cultivation of moderation, are dangerously fading through the amorphousness of Artificial Intelligence and the postmodern art of asymmetry. With the advent of the "variable geometry" period, the fragmentation of the post-war cohesion of the Western world, the increase in social inequalities between the powerful and the powerless, and the decline of values of solidarity and genuine information, are confirming the future overall upheaval that will run through the fabric of the world. And it is certain that from this creeping instability, phenomena of fear, threats, crises, and hybrid eruptions are born. Therefore, a cumulative re-evaluation of how the "great" govern is necessary so that the "small" can also enjoy. Our own moral "line" in front of the chaos of variables surrounding us must also be redefined. This is about a new social contract, where the "red line" of saving the planet from natural disasters and from the "hand" of Homo sapiens must be presented and implemented in the international community, not with wishful thinking but with actions and conscious positions and lines of salvation. The contribution of this book is to serve a purpose by opening a public dialogue towards enclosed lines, between monism and polyphony, between boundary and de-territorialization, between straight and curved lines, with the idea that each "line" often communicates but also fights, reconciles or opposes, depending on individual, overall, geopolitical, and spatial developments, with the "creative human" at the center