It’s easy to get the name of different things confused. Laymen do that all the time. They confuse transport circles with gates, thinking they’re the same things. But they’re not.
Gates are for moving things across different dimensions. Simple gates merely go to the Summerland or the Winterfell. More complex gates may reach into the astral or the elemental chaos. Gates can be used to summon beings from these other worlds as well. They’re not simple doorways.
Transport circles, on the other hand, are a means of getting around the world instantly, either by connecting with each other, or by acting as receiving pads for teleport rituals.
Transport circles have three modes – inert, passive, and active – and these modes are controlled by what those in the know currently call “keys” – though that’s not exactly what they do.
Transport circles also have a number of security measures built in to them, and that is what will be revealed here.
Each circle consists of three rings. The outer ring contains symbols that reflect the circle’s physical location on this plane. This is the circle’s address. The second ring consists of a string of interchangeable runes. This is the ring’s ward code – what some might call it’s password.
The third ring is where one would set the desired destination, and it is in this ring as well that the key would be set.
There are two types of key. A lesser key is needed to take activate an inert circle and to place it in passive mode. A master key is needed to put a circle in active mode.
A circle that is in passive mode can link to another passive circle by means of a special ritual as long as the user knows the other circle’s ward codes. A passive circle can also be reached by anyone using the teleportation ritual who knows both its address and ward code.
The master key makes the circle active. An active circle can teleport to any other circle whether its active or not. An active circle can also bypass another circle’s ward codes. This means that anyone holding a master key can use a circle to teleport to any other circle even when it’s key-less and inert, at any time, with no way to stop them.
It is theorized that there is a lesser key for each ancient teleport circle in existance. But it is thought that there are only a limited number of master keys hidden around. This is why any master key that may fall into the wrong hands poses an incredible risk.
There are those who believe as well, that a master key may allow a teleport circle to function as a gate between this world and teleport circles on other planes. But this has never been proven. The theory is based on the gateway that took humanity between Cordeia and Sy’Lum. That gateway had two keys, one on either end. The key on the Cordeia side was stolen, and from that point on people could travel from Sy’Lum to Cordeia, but there was no way to cross back, nor to contact anyone on Sy"lum to let them know the fate of the colonists.
No one remembers for sure now what the gate key looked like, whether any master key would work in that gate, or whether a gate key would be an even higher order of key. However, there are factions intent on learning how to open gates to forbidden places, and they will hunt down and take or steal any master key they can find to further their ambitions.
The circle on Vann Island is passive only. Until recently its only known use was for adventurers and agents of the Twelve Temples to use it as a destination for a teleport ritual. The circle was guarded by periodically changing its ward codes. An agent would be sent out with a specially ciphered text that would give him what the ward codes would be for certain specific days and times.
The circle outside Ver’nin was passive when first discovered. Then it was learned that there was a master key hidden within those ruins. The key was found, but later stolen and hidden. No one is certain who stole it, though it is suspected that a group of the indigenous people – the Abandonned – were behind the theft. Some say they stole it to protect it – that the White Lady came to one of them in a dream and warned her of a threat to the valley.
Hammer Durgin somehow came across the suspected hiding place of the key and sent out his most trusted agents in secret to retrieve it.