Abyss Gravity

Gravity is invisible, but it is the deepest obsession in the universe. In 2847, the Human Federation detected a gravitational wave signal at the edge of the galaxy that should not exist. Retired starship engineer Han Yuan was hired to investigate and discovered the wreckage of an ancient civilization battleship and the sleeping AI "Dawn" inside. Dawn informed him that there was a "Great Silence Protocol" in the center of the Milky Way - an automated eradication system created by an ancient fourth-level civilization that would systematically eliminate all civilizations whose technological development has exceeded the critical point. Humanity's gravitational wave technology has triggered the mark, with a countdown of about fifty years. This is a story about the survival of civilization, technological ethics, and individual choices.