This is volume 2 in Hollow Earth .

This book has been graded for interest at 8-12 years.

There are 400 pages in this book. This book was published 2014 by Simon & Schuster Audio .

John Barrowman has worked in TV, musical theatre and film, and stars as Captain Jack Harkness in Torchwood and Doctor Who. His sister, Carole, is an English professor.