Telepathic inhibitor

A telepathic inhibitor was a device connected to the stasis box. Part of its function was to control the entity; when used in the vicinity of individuals containing part of the gestalt, it triggered pain and disorientation in infected individuals. It could also prevent the entity from possessing additional people when activated. However, its power was limited, as it was unable to control the entity when the entire gestalt concentrated its essence in Peri.

It could also boost the natural range of telepathy, enabling the Fifth Doctor to remotely reprogram the TARDIS to cause a solar eclipse. (AUDIO: The Eye of the Scorpion)