Mystryl's Knot - During a bried discussion with Amon Therai after the Battle of Toldor, Archmage Mordenkainen refered to the Artifact as Mystryl's Knot:
A powerful artifact that powers The Magistery's Training Dungeons. It is apparantly a powerful artifact capable of much more that we have been aware. It was suggested that as we gain ranks in The Magistery we will be initiated into more if its mysteries. The Artifact is also at the center of a plot by the Illithids to infiltrate The Magistery and others in the Underdark seem to be aware of it and its power. It also seems that this Artifact may be sentient or at least act with its own agency.
"The Artifact, known to you as the training dungeon, doesn't do anything without a reason - everything you experience there is done with thought".
"You have Mystryl's knot here in the tower and you left it completely unguarded? I knew you were all rash, but by Baphomet's big ones, you need to keep a closer eye on your house."