First of all, I have to come clean. The Analysts are NOT entirely my idea. They are based on the characters called The Auditors in Terry Pratchett’s Discworld novels. In one of those novels, Thief of Time, the Auditors have gone a little more insane than usual and actually take apart a painting, reducing it to its component molecules of paint. The idea stuck in my head along with the idea.

Thinking up a new name for them was problematic. I needed something that had the same kind of meaning as ‘Auditors’ and was as impersonal and analytic. And of course, Analysts was perfect.

The second idea was that they might actually take a man apart in the same way. And what I had in mind was something like the music video Rock DJ by Robbie Williams, though possibly a bit less gross. I had an imagine in my head of The Doctor being disassembled that way and then reconstituted by the TARDIS being clever with temporal stuff. Originally, this was going to happen when Donna was a companion so that him being naked in front of her was a humorous moment, but that was done in Journey’s End, anyway and I really never got around to the storyline until after Donna had departed. Obviously, him being naked in front of Louise, his wife, is not so much a comedy idea so that particular dynamic changed.

I also wasn’t entirely sure which art gallery the story was going to be set in or which painting would be taken apart. I had thought of the National Gallery in London or the Guggenheim in New York, but as I already did a New York story, I decided against the latter. The National Gallery or the Tate Modern would have been good, but then I decided, also, to set a story in Paris. So, of course, the Louvre had to be the place.

Yes, I have read the Da Vinci Code, and know all about the scene with the Mona Lisa and the Madonna of The Rocks, which in that book is opposite the Mona Lisa. In actual fact, that painting is somewhere else. The painting opposite the Mona Lisa is the massive Marriage at Cana, which for my purposes was even better. It is a lovely high coloured picture of the sort that would appeal to Louise, who was used to a much more primitive style of art than the Rennaisance Masters, and seeing that reduced to a blank canvas would be dramatic.

The Mona Lisa, of course, is a very small painting, oil on a piece of poplar wood, not canvas. Personally I have never been particularly impressed by it. Portraits are not really my thing. Having it at the centre of things, though, does allow for the fun of finding ‘This is a fake’ underneath the paint. Everyone, of course, knows that The Doctor did this when he went back to Leonardo’s workshop in the City of Death episode! That was also the episode where the TARDIS became an art exhibit for a while. Leaving it in the Eiffel Tower to be a tourist attraction for a while was a reference to that, of course.

Hands up everyone who thought that French policemen were called Gendarmes? Popular culture seems to have stuck us with that idea. In fact, the Gendarmerie are the military police. The civilian police force is called police nationale and they have ranks like ‘gardien de la paix’ which is the equivalent in French of Garda Siochana in irish, both meaning guardian of the peace, and ‘sous-brigadier’ which I thought was such a fantastic word I had to have at least one of them involved. The Capitaine also slipped in nicely. Monsieur Gustave Dubois, senior art historian, was a late addition. I needed somebody who would be passionate enough about art to actually get in the way when the Analysts came back.

Whistler’s Mother, kept in the Musée d'Orsay, was a perfect subject for the second attack. From Rennaisance Masters to impressionists is a lovely cultural jump, and this painting is nearly as iconic as the Mona Lisa. Try NOT to think of what happened to it in the film ‘Bean’.

One problem with the resolution of the plot, when The Doctor is brought back by Louise turning the switch the other way, is that she really shouldn’t be that good with the TARDIS controls. This would have worked better with Donna in the companion role, since she would have been more likely to try pressing switches in the hope it would work. But that’s a niggle in my own mind. Nobody else seems to have been bothered by it.