Memory hub
From Tardis Wiki, the free Doctor Who reference
A memory hub was Ice Warrior recording technology that resembled a necklace. It had a homing signal so that others could track it. Shortly before her death, Alixlyr recorded a message on her memory hub inside the citadel of Peladon. She said there was "a secret which kills" at the heart of Peladon and warned not to trust the Peladonian royal family. (AUDIO: The Bride of Peladon)
