What is the author's tone in the nonfiction book, Midnight in Chernobyl?

Midnight in Chernobyl is a nonfiction narrative that flows like a story. It is mainly trying to tell a political history, presenting the science where it is necessary to explain where things went wrong, rather than trying to actually teach a rounded scientific lesson. Even though it is packed full of information, Higginbotham is careful to always be telling a tale rather than writing a history book. The tone is informative, and the book does not give any particular instructions or make much in the way of a persuasive argument. The only thing the author is really trying to convince the reader of is that the information he is presenting is relevant, but he does not have an otherwise specific message, just a few general biases that he appears to assume the reader will share.