Outpost Delta

 was a military observation station on the Gallifrey - Monan Host boarder. It was staffed with members of the Temporal Powers though at the start of Livia's presidency only the Time Lords and Warpsmith due to the increasing hostilities. Ace was sent there by Romana II to investigate whether the Monans where preparing for war. It was near a gravitation rift which Ace used to her advantage to dispose of a bomb. (AUDIO: Enemy Lines)