The Keystone, also known as the Eye of Opening, is an emerald. Given to the guardianship of the nockers, it opens anything it touches, regardless of whether the object is simply closed or securely locked and warded. It is powerful enough to open portals that lead to other realms, so long as they are not barred from the other side as well. Its true power, though, lies in its ability to open up the hearts of people and as a means of uncovering information that has been locked away or forgotten. It is a stimulator of memories.
Consider the user of the Keystone to automatically succeed if a point of Glamour is spent to open a locked or closed door, portal, or other item. These successes are added to a normal Dexterity + Security roll. Additional Glamour may be channeled through the stone to lower the difficulties to as low as three to open something that has been magically locked or sealed. While in possession of the Keystone, its holder cannot botch any security roll involving opening something. For purposes of uncovering information, the Keystone adds two successes to any roll involving Knowledges or Kenning. It confers the equivalent of Gremayre (Remembrance in 2nd Edition) on the bearer (subject to Storyteller discretion). The Keystone has been known to trigger a changeling's Chrysalis by its mere presence.