Following the mass migration 2052, most humans have left Earth for Mercury or Terrar, a star. The members of a religious cult that remained were killed by an explosion of its moon by Terrar in order to create a more efficient trade route to Mercury.
Even though the people of Mercury consigned the act, the deaths sent protest across the planet, and Captain Charlotte Jones is ordered to fly a 40-feet-tall bullet to annihilate the people of Terrar. With hundreds of days on the solo flight, Charlotte contemplates sabotaging the mission, but the autopilot on the ship maintains their course.
Upon the bullet’s destruction of Terra, Charlotte realizes that its people had sent their own bullet to Mercury, retaliating one genocide with another. Alone in her escape pod, Charlotte contemplates how immorally easy it is to live with genocide on your hands.