This zone is a heroic instance found at the back of the royal wing of Crushbone Keep's upstairs ( -59, 26, -42 ) /waypoint -59, 26, -42.
This is a larger heroic dungeon with several nameds who have a chance to drop legendary and fabled items. You will need to kill watchful sentries to unlock most doors. This will lead you deeper into the dungeon.
Using Escape in The D'Vinnian Throne will place you at the entrance to the zone but still inside the instance.
After you speak to her, she'll disappear, and two mobs will spawn. Kill them.
Now you need to kill watchful sentries for the keys. There is one in each room of the D'Vinnian Throne Room Instance. As you kill a sentry, they will drop a key which enables you to open another door. Sentries are 31 ^^^.
Eventually going through the rooms (Necromatic Chamber, Gladiator Training Hall, and a few others) you will reach Ograf the Deft level 33 ^^^ at ( -60, -9, -180 ) /waypoint -60, -9, -180. Once you kill him, the zone timer will be set, and you will not be able to enter for 18 hours, so be sure you want to spend the time in the zone before you kill him. He will also drop a key.