Wurth Harkin, Shank, and other Evermornan human slaves link up with the vbyifabids Gohro and Myrden and the emoxi pilot Rechet to hijack a consortium long-haul refinery vessel. After initially absconding from the planet, Wurth uses the ship's haul of cobalt to pelt the consortium's holdings in the system with relativistic, neutron-activated debris, rendering the system unable to support life for centuries thereafter.
Horrified at the humans' chosen form of revenge, Myrden demands that the Evermornans become signatories to the Valleybridge Accords to prevent any future destruction of habitable worlds at their hands. Wurth agrees, but Shank does not; ultimately, by a narrow majority, the humans do become signatories. Nevertheless, Wurth later lets it be known that he has more irradiated cobalt impactors in reserve should anyone else threaten Evermornan independence and survival in the Sealed Kingdoms.