If you gravitate (mavitate? If you know, you know) in and around the same circles I do, you can’t have failed to notice that it’s Doctor Who’s 60th anniversary this year.

Along with three special episodes, leading up to a Christmas special that’ll be featuring the Fifteenth Doctor, the BBC have also put together an absolute treasure trove for Who fans, with their Whoniverse initiative.

In the UK at least, just about every single episode of classic and ‘new’ Doctor Who (the latter being how the episodes from 2005 onwards are classified) are now available to watch, with a small number missing – either due to rights issues or being lost, which is a whole other story that we won’t get into here.

As such, I’ve been dipping in and out of classic Who, discovering stories for the first time as well as refamiliarising myself with stuff I haven’t seen for decades.

One such story that I don’t recall having ever seen beyond just a few clips is Spearhead From Space, which marked the first appearance of Jon Pertwee’s Third Doctor, as well as being the first time that Doctor Who was actually shot and broadcast in colour.

It’s a great story, which sees our new Doctor acclimatising himself to a new body and an unusual new situation – given that he’s been banished to Earth, with no TARDIS to whisk him away anywhere he pleases in time and space.

So he finds himself working for military organisation UNIT, alongside Brigadier Lethbridge-Stewart and scientist Dr. Liz Shaw.

The Doctor and his new team uncover a sinister plot to replace high ranking military and government officials with plastic, autonomous substitutes – yep, these are the Autons, an enemy used for the very first episode of the rebooted Doctor Who in 2005.

Despite classic Who usually feeling like it could do with a much bigger budget to realise its often very ambitious writing and concepts, Spearhead From Space looks incredible.

Particularly as it was shot entirely on film – the only classic Who series for which that was the case – giving it a realistic and bud budget feel.

The Autons themselves are incredibly creepy and brilliantly realised, though the Nestene Consciousness looks uncannily like a pulsating anus. Honestly, it really, really does.

Still, that doesn’t take away from how well written and produced Spearhead From Space is; it’s a fantastic introduction to Jon Pertwee’s flamboyant and wry take on the Doctor too, with him swanning about the place, dressed like a disco Dracula, cape and all.

Both the Brigadier and Liz play well against the Doctor too, with the Earth-based setup of this series forcing a grittier feel to the narrative.

Though it suffers from the slower pacing of the era at times, Spearhead From Space herald such an immediately interesting, unique era for Doctor Who; though Peter Capaldi’s Twelfth Doctor flirted with staying earthbound in his final season, he still had access to (and used) the TARDIS, regardless of how many disapproving looks he got from Matt Lucas.

I must admit that this is also the first time I’ve felt compelled to keep watching in order after finishing a story (yes, I’ve now moved on to Doctor Who and the Silurians already!).

I’ve dipped in and out of the main story points for the First and Second Doctors (missing episodes make it hard to worry too much about being a completist there anyway), but, on the strength of Spearhead From Space, I think I’ll be checking out the entirety of Pertwee’s run.