Synopsis
History
First publication: Ace Double #G-632, with The Rival Rigelians by Mack Reynolds, Ace Books, 1967
Review
Videos
We have the story in these editions:
The Rival Rigelians / Nebula Alert, paperback, Ace Books, 1967-00-00
All of the stories in the Empress Irene series:
1 Empress of Outer Space
2 Space Mercenaries
3 Nebula Alert