Griffin, a young bat, is sucked into the "Underworld," and his father follows to rescue him.
- ISBN10 1439107580
- ISBN13 9781439107584
- Publish Date 23 June 2008 (first published 1 January 2000)
- Publish Status Active
- Publisher Simon & Schuster
- Imprint Simon & Schuster Books for Young Readers
- Format eBook
- Pages 320
- Language English