Star Wars - Enemies of the Outer Rim
The Vault is ODIN’s high security facility located on the planet Opteras. While the vault specifically refers to the massive underground facility, it has come to be used to refer to the base in its entirety. The Vault is used for multiple purposes, primarily as a holding area for items of interest to ODIN, including persons of interest, technology, or artifacts which may be deemed to dangerous to allow free, but which cannot be eliminated.
The Seer, upon his pickup by Revan, has been kept within the vault for his own ‘protection’, as ODIN works with him, but does not trust him. When the Augur attacked the facility, her forces on the surface were a distraction while creatures under her control bored into the vault from beneath, allowing her to attack, and eventually kill the Seer.