Several fellow biophysics students meet many years after graduation. Their destinies intersect on the territory of the Zone, where the past and the present, mortal danger, love, hopes for the science of the future and memories of the destroyed research group, which was once assembled by their scientific supervisor, nicknamed de Treville, are intertwined. Then they were young and bore Musketeer names , the world concerned itself in a simple and understandable way, but now in the shifting swamps of the Zone it is no longer possible to understand: who is a friend and who is an enemy.