Therefore, its known narrative elements are not a part of the Doctor Who universe as we, on this Wiki, choose to define it. It may have been the basis for a similar story in another medium, however — and that story may indeed be valid.
The Hollows of Time was the fifth episode of the planned original season 23. It was planned to be written by Christopher H. Bidmead and directed by Matthew Robinson. It was later adapted into a Big Finish Productions audio play. It was also going to be the return of the Tractators.