Echoes of the Metal Mountain (Part 1) - Seb Astien's universe

From time immemorial, peoples and communities have created legends and stories, sometimes extraordinary, sometimes magnifying reality. The nomads who roamed the great western continent were no exception. Contrary to the consensus among historians and scientists that man has never flown through the air or left the ground, which is considered impossible, these tribes describe these events with astonishing accuracy. While one traveller sets out to explore this vast continent, driven by curiosity and a desire to learn about his own and the world's history, others are on the verge of breaking through the Earth's atmosphere on a mission to save their distant nation.
One has lived through a forgotten era, the others come from an imaginary world as far as human knowledge is concerned. Against a backdrop of unlikely encounters, legends collide with authoritative historical reality. And what if, behind these stories handed down from generation to generation, there is an unsuspected truth?