So we come, at last, to Doctor Who’s first story, consisting of a creepy one-episode prologue and a three-episode thriller set in pre-history, with early homo sapiens. Except it’s only really the first Doctor Who story for those lucky enough to have seen it back in 1963. (Or perhaps, for some unsuspecting gamers who have come to it on Twitch). For most of us, it’s our umpteenth Doctor Who story, come to us via video or DVD or latter day repeats, after having been hooked by dozens of stories which came after this one.

From that perspective, as one part of the sprawling armoury of the series, rather than its opening salvo, it’s a very unusual story indeed. It’s not goodies vs baddies. There’s no injustice to overcome. There’s just a group of mismatched people thrown into a bewildering and potentially deadly situation, forced to work together to escape. And disconcertingly, its first episode feels like the rest of Doctor Who we’ve seen, but its caveman installments feel like something completely different and unique.

For a start, the production team makes the brave move of presenting a supporting cast of early humans who can barely communicate. In a wise scripting decision, these grunts don’t grunt, but instead talk in short, simple sentences, not unlike small children. This just about works, although you can’t help but shake your head every so often when the spell breaks – which it tends to when the tribespeople struggle to describe something outside their experience and end up speaking in a kind of gentle poetry. My favourite is when chief nimrod Za (Derek Newark) realises he needs more information and says, “I must hear more things to remember.”

This quest for knowledge is one of the story’s themes. It’s Barbara (Jacqueline Hill) and Ian’s (William Russell) curiosity which draws them to the TARDIS in the first place, following unearthly student Susan (Carole Ann Ford) home one night, only to discover that she’s living in a police box and a grumpy old Doctor (William Hartnell) is hanging around suspiciously. Once sprung, the Doctor wants to protect the secrets of his technology, which he sees as the key to his and Susan’s safety.  It’s so important to him to preserve this knowledge, that he takes off with the teachers on board. In the other, hairier tribe, Za and rival Kal (Jeremy Young) are in a race to acquire knowledge of fire making, because with that knowledge comes leadership. As Za says, “the leader would have things to remember.”

The struggle for the position of alpha male happens in both tribes but the one between Za and Kal is a basic contest for dominance. The one between the Doctor and Ian is more interesting. Both can’t help but squabble with each other about the way out of their predicament. Ian is rightly suspicious of this haughty, dismissive alien, and the Doctor views Ian as primitive and uncultured as any caveman. They eventually reach a detente through recognising the other’s skills, but it’s trickier than a simple development of mutual respect. There’s much more strategy going on.

Take, for instance, when the Doctor saves Ian’s life in the second episode. There’s a scrap with the cave folk and Ian’s about to get a stone axe to the head. Just in time the Doctor bellows, “If he dies, there will be no fire.” It’s easy to see this as an early indication of the Doctor’s true, underlying character, but I think it’s far more pragmatic than that. The Doctor quickly realises that in order for him and Susan to escape this situation, he will need Ian’s physical strength. He admits as much in the next episode.

Similarly, after sparring over the best way to order themselves on their first escape attempt from the tribe, Ian eventually appears to concede the Doctor’s leadership role. It’s in the fourth episode, when the Doctor has tricked Kal into revealing himself as the Old Woman’s (Eileen Way) killer, thus turning the tribe against him. Apparently impressed by the Doctor’s quick thinking, Ian agrees that the Doctor is their leader. But I don’t think he’s given up so soon. Surely Ian’s just thinking that if they ever get back to the Ship, he and Barbara need the Doctor to let them on board again and to attempt to get them home. As Rose once said, you don’t argue with the designated driver.

Naturally enough for 60s Who heroines, Barbara is never in the running for leadership position. But she does operate as the TARDIS crew’s conscience. In the third episode, she’s the one who can’t leave Za to perish (he’s been mauled by a vicious jungle beast, sensibly kept off camera). She’s almost hysterical with fear just before this happens, so her decision to give up the dash back to the TARDIS to help their pursuer is initially seen, certainly by the Doctor, as an act of madness. Her compassion seems to have been futile; it buys them no particular favour from Za who incarcerates them again as soon as they’re back at the cave. But Hur (Althea Charlton) seems fascinated by this moment of kindness, so there’s the sense that the tribe might also end up learning the importance of compassion from our heroes, chiefly Barbara. Add this to the idea of collective action – that no one person is stronger than the whole tribe – and Za has a whole heap of things to remember, including some new socialist ideals.

Barbara’s desire to help people might have an impact on the tribe, but it’s lost on the Doctor. He’s famously callous in these early episodes in a way which we’ll never see again. It’s not just the moment where it looks like he might kill the injured Za in order to escape. Also in that sequence, he seems prepared to abandon Barbara and Ian to help the caveman, while he and Susan run to the TARDIS. And any chance that he might have been learning some kindness from these earthly teachers is dashed in the last episode. That’s when Barbara stumbles and falls on the final run to the TARDIS and the Doctor, tellingly, runs straight over the top of her.

I suppose, to be generous, he might just be in shock. He and his companions have been held in particularly gruesome conditions. They’re kept in that cave of skulls, even though the decomposing corpse of the Old Woman is in there too. Perhaps even worse is that the four of them are forced to watch the final, brutal fight where Za beats Kal to death, eventually smashing his head in with a rock. It’s then you realise how bleak this story is; never again will the show depict one man savagely killing another with his bare hands, no matter how cartoony the circumstances.

It ends up, as most Doctor Who stories do, as a peculiar but fascinating mix. On one hand, it’s startlingly grim – I just can’t imagine the show lasting long if it had kept putting its heroes through bloody ordeals like this week after week. On the other, with its almost lyrical caveman dialogue, it never loses the sense of the unreal. In some ways it’s very sophisticated; it takes the show’s educational remit and uses it both literally (this is how you start a fire, kids!) and also uses education as a theme. In other ways, it’s hammy and repetitive.

Whichever order we watch Doctor Who in, we always come back to 100,000 BC, in an attempt to try and uncover where the show came from. But it will never work – at least not entirely – because in its unique mix of poetry, tutorage and brutality, there’s never been another story like this first one.

LINK TO… The Invisible Enemy. Both feature the work of designer Barry Newbery.

NEXT TIME… Are we in Scotland? It’s time to go Tooth and Claw. But before that… a random extra: a look at the pilot episode.