| Issue | #8 |
| Published | [December] 1937 |
| Cover Price | 0.10 USD |
| Pages | 76 |
| Editing | ? |
| Notes | back cover is the same as the front minus the price. inside front and back covers are blank. On sale date for this issue was December 15, 1937. |
| Characters | Secret Agent X |
| Genre | Spy |
| Pencils | Charles Flanders |
| Inks | Charles Flanders? |
| Notes | back cover is the same as the front minus the price. inside front and back covers are blank. On sale date for this issue was December 15, 1937. |
| Letters | Typeset |
| Notes | intro page followed by a full page with just copyright 1937 by King Features printed on it. |
| Characters | Secret Agent X-9 |
| Genre | Spy |
| Pencils | Charles Flanders |
| Inks | Charles Flanders? |
| Letters | Charles Flanders? |
| Notes | last page of the book is blank |
| Reprinted | Secret Agent X-9 newspaper reprints from 1937 |