Publication Reading Order
| # | Title | Year | Buy |
|---|---|---|---|
| 1 | The Secret Island | 1938 | Buy from Amazon |
| 2 | The Secret Of Spiggy Holes | 1940 | Buy from Amazon |
| 3 | The Secret Mountain | 1941 | Buy from Amazon |
| 4 | The Secret Of Killimooin | 1943 | Buy from Amazon |
| 5 | The Secret Of Moon Castle | 1953 | Buy from Amazon |
| 6 | The Secret Valley | 2016 | Buy from Amazon |