Tantiss vault

Built inside the Tantiss Base at Mount Tantiss, the Tantiss vault was a secret and highly secure area critical to the Imperial cloning program. The sector was preceded by an antechamber observed by security cameras and guarded by ten Imperial royal guards who stood guard around the corridor leading to the vault's gate, while additional troopers watched over the antechamber from an observation room on top of the entrance. Behind the gate, which could be opened via an access card, was an additional corridor with at least six ray shield barriers which opened one at a time to allow a single person to pass through. The only individuals allowed access to the sector behind the corridor was the Chief Scientist of the Imperial Advanced Science Division, Tantiss Base's head of security Clone Commander Scorch and the Galactic Emperor himself.

One of the rooms inside the Tantiss vault was called the Necromancer Vault; this area housed a chamber with several reinforced capsules that served as specimen tanks related to Project Necromancer. The room itself was decorated with intricate red patterns on the floor similar to Sith temple designs and on a lower level than the rest of the vault, requiring access through a narrow staircase.

The specimens were kept in tanks of three different sizes, including human-sized ones, and were preserved for the event that successful M-count replication was achieved. The contents of this particular vault were regarded by Palpatine to be of the greatest importance to the Empire.

Another area of the Tantiss Vault was used as living quarters where Force-sensitive children were held. This section consisted of a large circular room with three circular tables in the center for the prisoners to interact with various hologames or other toys, which were designed to keep their minds stimulated. The prisoners were held in four windowless cells that were arranged around the room and included a tube where the prisoner's blood samples were sent through. Above the space where the prisoners were kept there was an observation deck for various Imperial scientists and personnel to observe them. The area could be sealed in a moment's notice in the event of an escape attempt and all access cards were disabled. However, an alternative exit route existed behind the removable tiles in the children's cells, as the blood sample collection tunnels were large enough to accommodate a child-sized humanoid.

Other locations inside the vault included a solitary confinement cell which was used as punishment for the children in the living quarters. The vault was also connected to the sublevel containment chamber where Zillo Beast clones were held.

In around 18 BBY, Galactic Emperor Sheev Palpatine paid a visit to Tantiss Base and was to see the progress in the vault on Project Necromancer. Chief Scientist Doctor Royce Hemlock then gave the Emperor a tour of the facility.

After Nala Se helped her medical assistant Omega flee Mount Tantiss, she was replaced by Hemlock's assistant Doctor Emerie Karr to the Chief Medical Scientist of Project Necromancer. Karr was consequently given access to the vault, where she discovered the existence of the child prisoners there.

Following Omega's recapture, she was returned to Tantiss and imprisoned in the vault alongside the other prisoners.