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 War was a novel Lawrence Miles pitched to the BBC Eighth Doctor Adventures range a few days after the 12 March 1999 debut of The Curse of Fatal Death. It would have featured Joanna Lumley's Thirteenth Doctor.
As BBC Worldwide retained the merchandising rights for countless old TV shows from the 1970s and 1980s, mainly sitcoms, Miles planned to feature many old BBC characters in the context of the War in Heaven, when "history's come unstuck and all these alternate histories are overlapping". This mechanism would have preserved the ambiguity of, in Miles' words, "whether the Thirteenth Doctor's canonical or not". Several elements of the story, including the War in Heaven and the Shift, were previously featured in Miles' 1997 novel Alien Bodies.
Despite being formulated within only a few days after The Curse of Fatal Death, The War was the second Thirteenth Doctor novel pitched to range editor Stephen Cole, the first being proposed by David A. McIntee. Miles never even received a reply to his email, and later speculated that Cole had mistaken his pitch for a joke.
In the story, the Thirteenth Doctor would have found herself in a concentration camp on Earth where the authorities imprison strays from other realities. This would lead to numerous cameos from BBC sitcom characters, such as the Doctor's cellmate, Norman Fletcher (Ronnie Barker's character in Porridge).
At the novel's climax, the Doctor and Captain Mainwaring from Dad's Army would have led a suicidal light-brigade assault against the Enemy's base. In accord with the war story trope of a main character secretly working for the enemy, Mrs. Slocumbe's pussy cat Tiddles — who never actually appeared in Are You Being Served?, but is the subject of numerous humorous double entendres — would have been revealed to be a conceptual entity working for the Enemy.