Forged by Osmos Gien.
A complicated series of overlapping Celtic knots that, when stamped onto the skin, cast a pattern that shifts continuously (supposedly making it impossible to replicate). When touched, it gleams in shimmering shades of silver.
Only the Gatreau gatekeeper and crowns (kings and queens) are able to use the key to stamp Tellurics.
Once a Telluric has the key, they can enter and exit Gatreau, both into the Common’s world and to the four kingdoms.