Acting, directing, and writing are all fine. It's mysteries set in 30's Africa, and uses many of the conventions of films of the time, but from a modern perspective - not unlike the approach taken in Indiana Jones - and it generally works well.
I'm usually the first one to quibble about technical errors, but this series was sooo well done that I never noticed any of the ones noted in other reviews here. Mind you, I had a hard time with Valentine shooting guns out of people's hands, and with a flaming homosexual in that time and place, but I just let the excellent story telling carry things along. Somehow, it seemed ** right ** that Valentine was able to shoot guns out of people's hands, and that there were Nazis lurking, etc.
One of the most enjoyable things on TV in a long time, and I hope there will be more. Let's have a DVD soon, please.