Have you talked to the Lady ?? (forgot her name
) She invites you to stay overnight and refers you to her guards. There are two guards...one in front of the stairway and one to the left of him next to an aisleway that actually leads to your room. The guard in front of the stairway is guarding the coffins
Just talk to the guard on the left and he asks if you're ready and upon a yes...the scene shifts you into the room.