Ecto-Space

Ecto-Space was a pocket universe. A version of K9 and his Mistress travelled there from another universe, and helped to fight slavery and oppression. (AUDIO: The Choice, The Search)

Behind the scenes
Ecto-Space, as portrayed in BBV Productions' Adventures in a Pocket Universe series, was implied to be E-Space, and its characters the Mistress and A version of K9 were implied to be Romana II and K-9 Mark II following the events of Warriors' Gate. Though BBV secured permission to use K9 from his creators and rights-holders Bob Baker and Dave Martin, they did not obtain the BBC's licence to use Romana, E-Space, and other elements of the Doctor Who universe. No explicit connections between those BBC-owned properties and BBV's counterparts to them could therefore legally be drawn.