| # | Book Title | Author | |
|---|---|---|---|
| 1 | Gustav Gloom and the People Taker | Castro, Adam-Troy | |
| 2 | Gustav Gloom and the Nightmare Vault | Castro, Adam-Troy | |
| 3 | Gustav Gloom and the Four Terrors | Castro, Adam-Troy | |
| 4 | Gustav Gloom and the Cryptic Carousel | Castro, Adam-Troy | |
| 5 | Gustav Gloom and the Inn of Shadows | Castro, Adam-Troy | |
| 6 | Gustav Gloom and the Castle of Fear | Castro, Adam-Troy |