N.B. there might (or might not) be spoilers in this article!

So here we are then: the final First Doctor story.

“It’s not like what you see on the telly.”

Ben, The Tenth Planet: Episode 1

As a serial The Tenth Planet is never quite the sum of his parts. I mean – are all ventilation shafts really large enough to fit a human! And with its inventive take on planetary astrophysics and plate tectonics, it does stretch credulity somewhat.

Of course some of its “parts” are those spare ones of arguably the Doctor’s second most infamous foe: the Cybermen. That introduction alone would be enough to make the story memorable – with their almost-cobbled-together design and sinister sing-song voices, the Cybermen here certainly make a suitably spooky entrance.

And actually, as unbelievable as it seems, the whole ancient-twin-planet-drifting-back-into-Earth’s-proximity is a wonderful pulp science-fiction idea. I love the Doctor’s prescience of events on Mondas too. That’s something we’ve not seen too much of before.

“This old body of mine is wearing a bit thin.”

The Doctor, The Tenth Planet: Episode 4

But, of course, even greater than the introduction of the Cybermen and the idea of twin planets is the revelation that the Doctor can change his appearance.

Even knowing what’s coming, even having seen the story many times before – as recently as 2013 thanks to its late DVD release – the regeneration (as it would only later become known) is a genuinely thrilling moment.

Watching it this time (thanks to Ralph Montagu’s excellent reconstruction using the soundtrack, telesnaps, 8mm film and surviving footage), I felt that same mixture of sadness and excitement that every regeneration I’ve seen on first broadcast has brought.

Indeed one of the joys of the past year has been, that in some way, William Hartnell has been my “current” doctor and I’ve been able to get some sense of how it must have been watching Doctor Who from the beginning for the first time all those years ago.