Telepathic recorder

A telepathic recorder was an jewel-like object or device that was essential to Vespiforms, containing part of their mind. It could be imprinted by intense and emotional thoughts, even by humans, and thereafter contained a sort of essence of personality or motivation to guide the Vespiform.

Vespiform had a strong tendency to keep their telepathic recorders close, even if that meant that they would havve to enter a dangerous situation, and if the telepathic recorder was destroyed, the Vespiform died as well.

One of these recorders was brought to Earth by a Vespiform known as Christopher. After its death in 1885, the recorder came into the hands of his lover, Clemency Eddison, who assumed it was a jewel and took it back to England, naming it the Firestone. Its jewel-like qualities were apparently impressive enough to attract a thief, the Unicorn.

In 1926 Christopher's son, Arnold Golightly, who had been locked in human form all his life, took on a Vespiform form for the first time due to intense anger. He promptly made contact with the firestone, which imprinted in him the mindset of an Agatha Christie-style killer, because Lady Eddison, the wearer of the firestone, was at the same time musing on the amazing plots of her books.

Golightly started taking Vespiform form to kill humans, but was soon killed as the recorder was thrown in a lake and he followed it, drowning. (TV: The Unicorn and the Wasp)

The telepathic recorder was recovered from the lake some time later, and after being auctioned off came in the possession of the Torchwood Institute. (Captain Jack's Monster Files)