This is instance uses the same map as the menagerie.
Main Gallery
There is a wandering mob of a Skeletal Patrol Leader and 4 Skeletal Warrior (lvl 50^^^ epic(x2)). The pathing will take this mob up to each doorway. They are on a repop timer of about 8 min.
The doors to the two side chambers and center chamber are guarded by 2 Fettered Guardian and 2 enslaved Thrall (lvl 48^^^ epic(x2)). These guards are also on a repop timer of about 10 min. Becareful with AOE close to the side chamber doors because you can pull another set of guards from inside the side chambers.
Right hand chamber
Just inside the doorway is guarded by 2 Fettered Guardian and 2 enslaved Thrall (lvl 48^^^ epic(x2)). On the bed is a Ar'ticae Cultist guarded by 2 Fettered Guardian and 2 enslaved Thrall (lvl 48^^^ epic(x2)). Clear this mob to open the other chamber door.
Left hand chamber
Just inside the doorway is guarded by 2 Fettered Guardian and 2 enslaved Thrall (lvl 50^^^ epic(x2)). Behind the crystal is a Ar'ticae Scryer guarded by 2 Fettered Guardian and 2 enslaved Thrall (lvl 50^^^ epic(x2)). Clear this mob to open the center vault chamber door.
Center Vault
The door to the Vault is guarded by Raegh the Protector (lvl 52^^^ epic(x4)).
Inside the vault the walls are flanked by 6 Ice Protector (lvl 51 ^^^).
Behind Ar'ticae (who is non-aggro) are an Ar'ticae Summoner and 2 Fettered Guardian and 2 enslaved Thrall (lvl 51^^^ epic(x2)). There is also a lamina Vaner (lvl 51). Once you clear this mob, Ar'ticae will immediately become aggro.
Ar'ticae has an uncurable noxious, a fire elemental and cold elemental attack.