What is the author's tone in the biography, Tesla, Man Out of Time?

The book's tone is rather personal. It is not the author's ego that has center stage, however. As befits the type of book that it is, the author tells readers all about someone else. The work is nonfiction.

There is a subtlety to the tone that is an exceptionally good fit to the material. The whole point is for readers to grow closer to this man. Cheney is somehow able to convey a feeling of closeness even though she is writing objectively.