I used to LOVE Dee Henderson books. I haven't been as pleased with her new books as I was with her older series. I got bogged down in the details in this book. While I am sure some of the information about how submarines work was essential to the story, it seemed there were WAY too many details and technical terms and I found it very boring at times. Because of that, it took me awhile to get through the book. I liked the characters and the storyline other than that though. Undetected is basically the second book to her Unspoken book, although it isn't necessary to read Unspoken in order to understand Undetected, they are separate stories. Overall the book was ok, not up to the standard of her older series though.
I received a complimentary copy of this book from the publisher in exchange for an honest review.