After defeating the mages the party agrees to help the Aboleth to escape the dungeon in which he’s been placed. They question one of the defeated mages who reveals that the headmistress is an imposter who is only pretending to be Agera the headmistress of the Jade Tower. The party attempts to lead the Aboleth to safety, and encounters guards in the hall. See Here.
After the encounter the party discovers a hidden passage in the wall, and the Aboleth takes his leave at the entrance to the room containing the underwater passage to the underdark. The party makes their way to the place where Agera (Alara) is hiding and waiting for them. They take up arms against her, and are nearly beaten back, but emerge victorious in the end. Then they decide that they must move quickly to rescue the real Agera, and leave to do so. See Here.