In 2003, sixteen-year-old Kiyoshi Shirane discovers a black metal fragment buried in a Jurassic layer. Twenty-two years later, that impossible object leads him and data scientist Lila Manabe from an anomalous scar on the Moon to a massive structure sleeping beneath Siberian permafrost. What they uncover is not alien: it is the remains of an advanced Earth civilization from 150 million years ago. As Japan, Russia, and the United States converge on the site, the expedition finds a dead captain, a protected egg, evidence of an even older Civilization Minus Two, and a warning linking geomagnetic collapse with extreme solar activity. The first volume of ±0 Civilization follows the discovery that rewrites Earth's history—and points next to Mariana.