| title | ISBN-13 | year of publication |
|---|---|---|
| The Trap-Door Maker: A Prequel to the Phantom of the Opera | 978-0-9773866-3-5 | 2008 |
| The Trap-Door Maker: A Prequel to the Phantom of the Opera, Book 1 | 978-0-9773866-0-4 | 2005 |
| The Trap-Door Maker: A Prequel to the Phantom of the Opera, Book 2 | 978-0-9773866-1-1 | 2006 |
| The Trap-Door Maker: A Prequel To The Phantom Of The Opera Book 3 | 978-0-9773866-2-8 | 2006 |