The Faceless Ones. I watched the black and white version with the two existing episodes. (It seems a downright odd thing to do to animate the non-missing episodes as well as the missing ones but there you go).
As often seems to be the case with the classic series the first episode was a cracker. Thereafter, it felt very padded and the plot made no sense to me at all. The "Chameleons" want to use human bodies because their own faces have gone a bit icky? Was that it? Not for the first time, nor the last time, the departure of companions, in this case Ben and Polly, is handled horribly. On the plus side, the performances were all very good and I appreciated the opportunity to see this serial for the first time, albeit part-animated.
I've been listening to a podcast about the missing episodes, which took me right back to those dim and distant days in the last century, which was when many of us first became aware just how many 60s episodes (and colour Pertwee episodes) of Doctor Who were AWOL back then. In the 1981 DWM Winter Special, there was an interview with Sue Maldon of the BBC Archives, and at the end of the interview, this listing of what was then known to exist (with a couple of errors - Episode 6 of The Wheel In Space existed but was omitted, and Episode 4 of The Invasion was listed but was actually missing (and is still missing!)
At the time, it made bloody depressing reading. Being at the time innocent of the vagaries of TV archiving, I'd previously assumed that they were all safe and sound at the BBC. In fact, I was aghast - how could they have got rid of the likes of Tomb Of The Cybermen and The Ice Warriors - after all, the Target books were great, they had iconic monsters in them, and even though this was very early in the home video era, the thought that I would never be able to see them was deeply upsetting.
I was also very (possibly more!) upset that so many of the Pertwee stories only existed in B&W, and one episode (Invasion Of The Dinosaurs 1) was missing. I mean, I could remember watching that one at the age of 6 in glorious full colour, and it was completely gone forever! How could that have happened?
Since then, 42 episodes have been returned to the BBC (plus, through various returns and technological jiggery-pokery, all the B&W Pertwee episodes now exist in at least some form of colour!) We've also got odd clips here and there, a full set of relatively prisine off-air soundtracks for all missing episodes, off-screen telesnaps for many of them, and the ongoing animations (one of my favourites, Fury From The Deep, is coming next.) I can go on Britbox and access every single complete story (and a sizable chunk of animations and recons) at the click of a remote. I've been making my way through the classic era during my enforced break from work, and by heck, if I haven't fallen in love with this silly old show all over again! I'm currently up to The Pirate Planet, with all the "joys" of Season 17 and the 80s to come!