My opinion on the book is based on the following points:

First,  Rockwood’s writing style is fast-paced and easy to understand. The author's use of clear and simple English make it suitable for young readers or anyone who is in for a smooth read. Also, the dialogue between the twins feels natural and direct for the book's pacing. It exudes both their close relationship as brothers and also their differing personalities.

Second, the book was a page-turner. Each chapter ended with a cliffhanger that moved me to continue and even the plot had gripping parts that kept me unhinged. An instance of such a gripping scene was when Dan saw a cloaked ghost (he actually later discovered it was a human) appearing before him every night. I actually felt so scared for him, and I was unable to detect what was about to happen next.  Aside from that, the chapters, although short, had an appropriate balance between humor and mystery.

Lastly, the characters, Dan and Paul, were great together. Their contrasting behaviors, personalities, and temperament makes them a perfect team. While Dan is the fearless one who often acts before thinking, his twin brother Paul is seen as the gentle one who prefers to avoid consequences by thinking before acting.  Take for instance, in one scene, Dan wanted to enter a dark tunnel without letting anyone know, but Paul was concerned about letting their mother know for safety reasons. This scene clearly portrayed the twins' opposing characteristics.  However, despite their differences, they trusted each other and worked together to uncover the mystery.

In conclusion, the Dungeon of Peril Mystery book is a blend of suspense and investigation which is perfect for young adults, fans of detective books, and lovers of adventurous books.  Also, teachers and parents who are looking for a captivating fiction book for their children or students should also buy this book.