| Chicken House, January 1, 2008, cover price $17.99 | About this edition:
When Will Burrows and his friend Chester embark on a quest to find Will's archaeologist father, who has inexplicably disappeared, they are led to a labyrinthine world underneath London, full of sinister inhabitants with evil intentions toward 'Topsoilers' like Will and his father.
| Reprint edition (Scholastic Paperbacks, February 1, 2009), cover price $8.99
| Abridged edition (Bbc Pubns, January 1, 2004), cover price $16.75 | About this edition:
| Turtleback Books, February 1, 2009, cover price $19.65 | About this edition:
FOR USE IN SCHOOLS AND LIBRARIES ONLY.