The Rings of IkiriaSynopsis :
UNIT is accustomed to dealing with visitors from space, but nothing has prepared them for Ikiria, an alien artist bearing gifts. Could Ikiria’s designs be something more than aesthetic?
As the Brigadier turns against him, Mike Yates goes on the run. Can he save the world? Or will he just learn an important lesson in betrayal? Casting :
Captain Mike Yates - Richard Franklin
Ikiria / Corporal Jean Mercer / Mrs Oliver - Felicity Duncan
Source : http://tardis.wikia.com/wiki/The_Rings_of_Ikiria_%28audio_story%29