Secret Agent X
Titles (11)
| # | Title | Author(s) | Year | Type |
|---|---|---|---|---|
| 1 | The Torture Trust | Paul Chadwick | 1934 | |
| 3 | The Death-Torch Terror | Paul Chadwick | 1934 | |
| 5 | City of the Living Dead | Paul Chadwick | 1934 | |
| 6 | Octopus of Crime | Paul Chadwick | 1934 | |
| 7 | The Hooded Hordes | Paul Chadwick | 1934 | |
| 8 | Hand of Horror | Emile C. Tepperman | 1934 | |
| 9 | Servants of the Skull | Emile C. Tepperman | 1934 | |
| 12 | The Sinister Scourge | Paul Chadwick | 1935 | |
| 14 | Devils of Darkness | Paul Chadwick | 1935 | |
| 20 | Ringmaster of Doom | G. T. Fleming-Roberts | 1935 | |
| Curse of the Mandarin's Fan | G. T. Fleming-Roberts | 1966 | Anthology |