This quest is not available in game.
Visit Joseph the Insane.
Our renewed forces can handle the situation here for a while without you. I've received reports that Joseph the Insane, a former Scarlet Crusade officer, is in the Scarlet Monastery Cathedral and is taking his band of renegades to strike out against Scarlet Commander Mograine.
This is an excellent opportunity. Go there and help him with his insane task, and maybe we can use the Monastery as an excellent stronghold right at Sylvanas' doorstep!