More like 3-1/2 stars. Not quite as good as the first book, in my opinion, but still entertaining. I really like Joe Tesla and Edison. I feel like there wasn’t as much time spent beneath the city in this installment and a little too much time was spent with the villains of the novel. I am looking forward to book three, though. Again, solid narration by Jeffrey Kafer. Definitely recommend it in either print or audio format.