Apparently it wasn't a time for trying to knee people in a tightly enclosed space, either. The forming Cluster down below rocked the planet again, and then a wave of white-light arms came crashing up towards them at just that very moment, rocking the drill violently.

Peridot lost her balance. Peridot got that incoming knee to the face, leaving her swinging back the other direction again, arms in the air and tiny legs akimbo as the wave receded again.