What is the author's style in A Test of Wills by Charles Todd?

The language and word choice in the story tend to be upper crust British, but not too snooty. Ian Rutledge has had a privileged upbringing, but he is not a member of the aristocracy. However, he is comfortable among the landed gentry, who generally served as officers in the wars. His comfort in this environment is reflected in his speech and thoughts which make up the bulk of the book, and is contrasted with Hamish McLeod's more working class observations in his Scottish accent.