From WoWWiki

The Viewing Room is a chamber within Scholomance. It is accessed from the eastern branch of the large unnamed central chamber.

The door to the viewing room is locked and the key can only be obtained from Rattlegore, who can be found in the Great Ossuary, south of the central chamber.

Inside the Viewing Room are several students, as well as their tutors, Marduk Blackpool and Vectus. These NPCs will not attack players passing through the room unless one of the players uses the Dawn's Gambit, which turns all the students into hostile non-elite skeletons.

Most groups will leave this room unmolested unless one of the players is attempting to complete the quest  [60D] Dawn's Gambit.

The two exits from this room lead south to the Laboratory and east to the Grandmaster's Study and ajoining chambers.

Notes

• There is a persistent rumor on many servers that you can NOT talk to the students, Marduk nor Vectus, because doing so will cause them to aggro. This is a blatant fallacy, as the both the students and their peers will willingly chat with players without any hostility.

Subzones of Scholomance
Barov Family Vault • Chamber of Summoning • The Coven • The Great Ossuary • Hall of Secrets • Hall of the Damned • Headmaster's Study • The Laboratory • The Reliquary • The Shadow Vault • The Viewing Room • Vault of the Ravenian