Oh dear. Half way through episode 4 of "The Church and the Crown", writers Cav and Scott decide to have the Doctor attempt to explain the point of changing history in historical adventures of this kind. Bigger writers than them have tried before and failed, so it seems at best a foolhardy venture, at worst over-confident smugness. Like Davison's Doctor similarly starting "Arc of Infinity" by launching into an explanation of how the Cybermen could use guns in the TARDIS in "Earthshock", it's struggling needlessly to answer a question nobody sane thought of asking in the first place. So why bring the matter to attention and make trouble for yourself?

It is, though, better to have a game attempt once the matter has been raised, (as the mystical "nobody's perfect" farce of "Arc" demonstrated). Here we learn that the Doctor and his friends were always part of history, but this still doesn't explain the Doctor's conveniently instinctive knowledge that they are guiding it along its correct path by interfering, rather than perverted its course as the Doctor has claimed so many people he's tried to STOP changing history were doing. So how are the Doctor, Peri and Eremim simply playing their part when Linx in "The Time Warrior" wasn't? The unhappy conclusion is that the Doctor knows how every strand of history unfolds, or else we're back to some kind of "Time Lord gift" that renders the entire explanation exercise farcical. Who's to say that the weapons Linx left behind didn't influence a perfectly natural historical discovery? Or perhaps when the Doctor meddles with the past it "always happened", it's only when anyone else does it that it's catastrophic. You can't win, so leave it be boys. We'd not even thought of it until you said.

Ironically, the notion of the Doctor completing an adventure because it's what he should do, rather than for any better reason, stands as a chewy metaphor for "Church and the Crown" itself. This is a play whose reason to be is more important than what it actually is. Big Finish's obvious desire to "do something swashbuckling" overrides the importance of what actually happens between TARDIS landing and departing at opposing ends of the tale. Consider that only a madman would expect them to commission "a story set in the present day" without further sketching in of point or plot. But historicals, seemingly, are different. The flavour is everything, thus ensuring this story is packed tight with horses, musketeers, Kings and Cardinals makes treading water such fun that one almost forgets to ask what the point of it all is. Except Peri, of course. And how telling the Doctor can't give her a straight answer?

"Church" revels in being its own most important reason for existing. Even Peri seems to be an absurd exact-double of Queen Anne because that's what frequently happens in these things. Just as the Doctor explains that history is taking its natural course, Peri's question over the point of the enterprise is inadvertently answered by telling us that there isn't one. The antithesis (and contradiction) of the doom conjured up in "Pyramids of Mars" when the Doctor shows Sarah how Sutekh could destroy the Earth by changing time, "Church" is a story happy to confess that nothing is going to change. We're here for the fun of the ride. In short, it's all a bit of a laugh really.