Big Finish love stories. They also love to join the dots and play 'What If'. The urge to revisit a half-developed idea which might briefly have played upon the mind of a harassed TV writer before finding its way into one of your favourite stories can be irresistible.
And who can blame them? They have the entire canon of Classic Doctor Who as their sandbox. You'd probably do the same, the only restrictions are availability of cast, mostly through mortality - and for some characters death is not proving an end, as heard in the Lost Stories, Early Adventures, and the forthcoming Third Doctor Box Set.
In this, the opener of the latest series of Fourth Doctor Adventures, self-proclaimed biggest fan of Death to the Daleks Nick Briggs decides to put some flesh on the bones of the Exxilons, a race that we know slipped into savagery after building their great city. We know that the friendly ones live underground and glow a bit in the right light. We know that the unfriendly ones are grunting, spear-wielding primitives. And, we know that their great city, in the grand tradition of deserted great cities of Doctor Who, is a bit of a swine.
Arriving on a developing planet, the Doctor, Leela, and K9 find themselves in the middle of a conflict between outwardly civilised humanoids, and some grunting, spear-wielding primitives who have been put to work building a mysterious structure. The Doctor and his companions are separated - he ends up with the primitives, meanwhile, Leela and K9 fall foul of the alien visitors and the malign power of their structure.
However, just as you think you know where this is going, Writer/Director Briggs pulls the rug. The race with the spears aren't who you think they are, they're called the Tarl. The advanced civilisation who had the 'deal' with them (effectively ended by the death of the Tarl leader's son) are the race that will one day end up smashing up a Dalek with rudimentary weapons in a quarry.
The Exxilons are using the Tarl to build a beacon to transmit across the stars and power their great city, a sentient city that they serve. It fills their heads, and gives them orders. It also attacks the minds of all that aren't Exxilons, and drains them, even the brains of Time Lords aren't safe. Aside from this though, they're a long way off the race depicted in Death to the Daleks, they sound nothing like the Exxilons from that story, and clearly look nothing like them either, as it takes a while for the Doctor to put two and two together, and tribe leader Ergu (Tim Treloar) has to do the name-dropping. How the Exxilons we meet in this story become that race is hinted at, but largely left to the imagination when one of their number, Trexa (Daisy Dunlop) rebels against the city, having bonded with the late son of the tribe leader.
Dunlop is the strongest of the guest cast, giving a spirited performance as the spirited junior overseer who develops a conscience. Treloar is also good as Ergu, given the tough gig of having to portray a monosyllabic tribe leader he manages to strike up a good rapport with the Doctor, who he dubs "Everywhere Man". Tom Baker and Louise Jameson are both very good here, their performances are pitched just right. Several series and a few box sets in, one of the best Doctor and Companion pairings ever are quite possibly better than they ever were together on TV.
The rest of the small cast are more of a mixed bag. Jacqueline King as Calura is perfectly good, but is unrecognisable behind a puzzling American accent, and Hugh Ross as villain Gethal is a bit all over the place - one minute coolly officious, the next he's chewing the scenery like a Drashig. Maybe Briggs will bring back the Exxilons to bridge the gap. Their loss of identity should feel tragic, but instead it feels like they deserve to fall as a civilisation and that's that - a little unfair for a species ruled by their evil city, who will one day end up as frog-eyed, bark-skinned savages when the city rejects them. The Exxilons aren't the nicest people, but there's surely a pay-off in the waiting. Still, minor quibbles aside, this is a strong season opener, both well-executed and pacey.