By Alexander McCall Smith
Author of The No1 Ladies' Detective Agency
Every author must be anxious about books being made into films, but not every author had the good fortune that I did of having Anthony Minghella as his director.
Minghella's films are cinematic gems, and so it was certainly not with heart in mouth that I went out to Botswana last July to see Minghella and his team in action.
The first thing that struck me was the size and bustle of the whole filming operation.
Military campaigns must have nothing on filming, with what seemed like thousands of people milling about talking into radios, moving cables, serving sandwiches and so on.
The author went to Botswana to see his novel brought to life
In the middle of all this I found myself meeting Jill Scott and Lucian Msamati, respectively Mma Ramotswe and Mr J.L.B. Matekoni.
Oddly enough, although I created these characters, I have never had a clear picture in my mind of what they looked like, other than that Mma Ramotswe is traditionally-built (that is, large) and Mr J.L.B. Matekoni has a kindly, rather put-upon expression.
Both actors seemed ideal. Jill Scott had a wonderful calm modesty about her, as did Lucian Msamati.
When I was introduced to them, I felt that I was meeting the real characters - and it was all very natural and easy.
Minghella's eye had done its work: he had believed that they could do the roles and he was right.
And as for the set - I was astonished at the attention to detail that was shown in the construction of a Botswana street scene.
Everything was just as it should be: the real spirit of the country had been captured.
Then Minghella showed me a clip of the previous day's shoot. It was a very moving scene and I was completely overcome. He had pulled it off. Perfect.
I did not know, of course, that this was to be the last film made by that good, kind man.
I count myself immensely fortunate that he made this film, and that he made of it such a marvellous combination of humour and feeling.
The No1 Ladies' Detective Agency will be shown on BBC1 on Sunday at 2100 GMT.