Ultra-beam accelerator

An ultra-beam accelerator was among the devices used by the human survey team on a jungle planet. After they degenerated into the Sevateem, it was believed to be a relic of Xoanon. When Neeva was using it in a ritual, shaking it as he circled the Fourth Doctor, the Time Lord warned that if there was a charge in the device, the village could be turned into a "smokey hole in the ground." (TV: The Face of Evil)