Interesting historical fiction about one of the most fascinating figures involved in 19th century technology. If you don't know the facts, rumors, and speculations about N. Tesla, give the Google machine a whirl. You might be lost for hours. This book pulls in facts and speculation into a rousing action story about alien invasion and the real historical characters who engaged in science, technology, and industrial capitalism at the time.
It is a relief to read “steampunk” fiction that deals with real science. I have not had much reading success with fantasy steampunk. However, this hard science take on the steampunk age was refreshing. This book was very much styled like the greats of Golden Age science fiction, like Heinlein or Asimov. I felt like I was reading a story by A. E. van Vogt, one of my favorites.
Let me talk about Miss Clara. This major supporting character steals the book, for me. I enjoyed reading about a Victorian woman who could take care of herself and did not wait for a man to rescue her. Clara kicks butt, charges into danger, and rescues her man, when necessary. It was fun to see how she would deal with each challenge that was thrown at her.
I would recommend this book to readers interested in a fantastic tale of historical fiction. This book is suitable for middle school and up. There are some sexual activities described in flowery Victorian terms that most parents will probably find acceptable. There are scenes of violence and loss in the story, but it serves healthy plot development and is not gratuitous. My biggest warning would be about the hard science nature of the story. Any reader who cannot get through Golden Age science fiction stories may have difficulty with Tesla's Signal. The book is filled with real science, real history, and real characters. Otherwise, give it a try. You may find an exciting new author to follow.