The colony starts to establish itself on Belle Terre, but then Spock realizes that the Quake Moon is filled with quasar olivium and will explode in about 8 days. An attempt to relieve the pressure on the moon by loosening a section of the mantle using tractor beams fails, with the loss of six ships and damage to others. The colonists evacuate to the remaining ships (except for 6 children who hid themselves, and one mother who stays to try to find them). An attempt is made to redirect an asteroid at the moon, to weaken a portion of the moon's mantle and relieve the explosive pressure, although it is realized that radiation will leave a large part of the planet uninhabitable for a long period of time. The effort to move the asteroid nearly disables a few more ships, but it is ultimately successful, and the six children and the mother (Lilian Coates) are saved from the radiation by sheltering in a cave. While this has been going on, a survey ship (the Rattlesnake, captained by Sunn) had been sent out to try to find another suitable planet. They locate one that had previously been inhabited, but the inhabitants had died mysteriously. They finally discover that the planet had been affected by a mysterious black entity that drained all energy. Heading back to report the findings to Kirk, the ship encounters the same object, and they get too close to it, losing all their energy, and the crew dies due to lack of life support.