Doctor Who: Shada

Intended as the finale to troubled-plagued season 17, this was the only story that was canceled over mid-way through production due to a most unfortunate strike at the BBC. Tom Baker stars as the fourth and most popular Doctor, with beautiful Lalla Ward as his companion Romana (II), and of course K-9(voiced by David Brierly for this season only) that finds them visiting 1979 Earth to see old friend(and fellow Time Lord) Professor Chronotis(played by Denis Carey) at his University, where they learn that an ancient book from their home planet Gallifrey has been stolen by evil scientist Skagra(played by Christopher Neame) in his plan for universal domination.

Uneven plot(typical of this season) has fine acting and nice location filming, but some silly elements as well that detract. What the end result would have looked like is speculative, and a great pity that it wasn't. Tom Baker introduces this, and first released on VHS in 1992, then 20 years later on DVD, where at least fans can have the opportunity to judge for themselves on what would have been a six-part adventure, though counted here on IMDb as one story.

Still should be considered as canon, since it was (visually)referred to later in anniversary story 'The Five Doctors'.