‘Don’t come all clever dick with me.’ Ian Briggs’ script is full of allusions that sound clever but don’t quite add up to anything substantial. Here, there’s a lengthy sequence that plays like a pastiche of Aliens, except this time it’s the xenomorph that rescues the little girl from the tough woman with a gun. It’s nice to have another Doctor Who story where the “monster” turns out to be one of the good guys and it’s people who are the real threat – it’s been done, but not so often it’s boring and the difference between Dragonfire and something like The Creature from the Pit is that here the dragon is pretty much established as something to be protected from the beginning.

Like Delta, there’s a brutal streak to this that’s a bit jarring: having all the happy shoppers exploded on the Nosferatu is less grim because we haven’t got to know and like them, but even so I was half expecting the Doctor to reveal the ship was empty and he’d come up with a clever plan for them to escape. Instead, they drift unmourned through the void, while Kane, having realised his revenge quest is futile, quickly makes good on his long-winded promise: ‘I considered journeying round from the cold dark side of Svartos to the sun blistered surface on the other side, where I would quickly die.’

The real story is Mel’s departure and Ace’s arrival. Mel’s final scene is, possibly inadvertently, a nice nod to her strange anachronistic non-introduction, and my personal fan theory is she exists in a closed time loop and has realised that, reunited with Glitz, this is where she came in so it’s time for the two of them to head off to their date with Colin Baker (the long way round). I enjoy Bonnie Langford’s performance more the older I get, and I appreciate Mel’s boundless enthusiasm as a contrast to the surliness of her 1980s predecessors. Still, I reckon Ace’s reaction to her suggestion of a game of I-Spy sums up the feelings of many viewers.

Ace is a more obvious fit for the kind of stories Cartmel and JNT are going to go on to produce over the next two series. I particularly like the fact that she’s not immediately self-sacrificing when Kane tries to bargain with the Doctor for her life: like most 16 year olds she doesn’t want to die. She’s got a believably “as if” attitude, and a good balance of naivety and toughness. I really like Ray, but I think Ace is marginally the better fit.

And that’s Season 24. I’m indulgent towards it partly because it’s the first series I properly remember from being a kid (I was watching from The King’s Demons, but only recall snippets) and partly because, for all its uncertainty of tone and frequent ridiculousness, I think it understands the Doctor and the series. The things it gets wrong are less egregious than the faults of the previous five years. On this pilgrimage, I struggled with the constipated dialogue and characterisation of a lot of the Davison and Colin Baker episodes, scripts that frequently gave the impression that the Doctor wasn’t up to the job, and a solemn approach to the show’s history. Within 14 episodes that whole approach has been forgotten. It’s not quite there yet, but for the first time in ages this feels like things are on the up.

Next episode: Remembrance of the Daleks