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.
Night of the Spectre was to have been the final of four Halloween specials for The Sarah Jane Adventures, but due to the death of Elisabeth Sladen was never produced. Unlike the other Halloween specials that were to be live broadcasts, Night of the Spectre was to be animated.
As this was the last of the Halloween specials it would have been succeeded by a sixth series. (DWMSE 32)