The call
The Call‏‎ 

When the Universal Collective was defeated and a small band of survivors came to Koken , they found an ancient chamber constructed by an unknown but highly advanced civilization. They found 'The Disc ', a device created to detect and find the Twelve Token (The Disc has all locations recorded. It was created by the Dualix , in order to restore the Rule to the concept of Duality) They also found a device that connected to the Crucible . The Survivors elected the Ker to be their "Successors" and left one part of the device with them, so they could issue The Call for whatever weapon the Crucible was creating.
The Survivors found the Crucible in the Leo II galaxy and installed their own AI over the old one .
The Survivors were slain by a creation of the Crucible , but the device and the connection remained.
The Ker , now evolved into the Kermac . Used the device to issue the First Call and all subsequent ones.
The Call is a Hyperspace communication that activates the Crucible, telling the ancient system, a Token was found or a species that has the potential to become host to the Dark One .

See also the Sequence

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