The galaxy is at war between the oxygen-breathing Terran Federation of worlds and the Ginzoes, chlorine-breathing aliens. An Earth ship is captured in battle by the Ginzoes, and its crew learns that the aliens have a newly developed catalyst. This can liberate chlorine from the sea -which, for the Ginzoes, would convert Terran worlds into suitable environments. The catalyst will be used unless the Terran Federation declares peace within fifty days. Fifty days to save Mankind...or fifty days to doom!
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| 1954 |
|
The Extra Man | Milestone Publications, Ltd. | Novel | |
| April 1959 |
|
Verräter zwischen den Sternen | Moewig | Novel | 1 |
| December 2000 |
|
The Extra Man | Cosmos Books | Novel | |
| June 2010 |
|
Fifty Days to Doom | Linford / Ulverscroft | Novel | |
| September 2011 |
|
The Extra Man | Gateway / Orion | Novel | |
| December 2013 |
|
The Extra Man / The Space-Born / Fires of Satan | Gollancz / Orion | Omnibus | 7 |
| January 2014 |
|
Fifty Days to Doom | Gateway / Orion | Novel | |
| September 2021 |
|
The Extra Man | Wildside Press | Novel | |
| September 2021 |
|
The Extra Man | Wildside Press | Novel | |
| August 2022 |
|
The Extra Man | Wildside Press | Novel | |
| November 2022 |
|
Fifty Days to Doom | Wildside Press | Novel | |
| November 2022 |
|
Fifty Days to Doom | Wildside Press | Novel |