Telepathy pendant
The psychic equivalent of an easdropping device, the telepathy pendant allows the wearer to listen to the thoughts of others. Mary gave Toshiko Sato, the pendant as a gift. Still passing herself off as a Human at the time, Mary seemed to indicate that she obtained the pendant off the alien artefact gray market, though it may equally have come from Mary's home planet.
- Mary said that her people used telepathy rather than words though she did not say if they used technology to do so. Sarah Jane Smith's friend of the same species as Mary did not need a pendant to communicate with Sarah. Mary may have really gotten the pendant off of the gray market, as she had claimed.
When worn around the neck, the pendant enabled Toshiko to easedrop on the thoughts of people around her. This presented a drawback because of the overwhelming number and volume of thoughts that Toshiko exposed herself to in this way as well as confusing her as to whether her thoughts originated in her own mind or that of other Humans. Mary shielded her thoughts. When in Jack Harkness's proximity, she could not read his at all. Jack could project thoughts to her, if he chose, but she could not read his personal thoughts.
Talking it over with Jack and unsure what to do, Toshiko decided that the pendant's abilities powerful enough to change the world. She then decided to crush the pendant underfoot, destroying it, after talking matters over with Jack(TW: Greeks bearing Gifts).