Thesanius was a Pakhar and a friend of the Doctor. He could supply him with materials that the Doctor needed for his TARDIS. The Fifth Doctor helped him escape from Garazone security. (AUDIO: Nekromanteia). He also knew of Bernice Summerfield and told her to go to Cantus, though neither Benny nor Jason Kane knew of him. He was later killed in an explosion. (AUDIO: The Crystal of Cantus)