- Script
- Stan Lee (credited) (plot, script - see notes); Larry Ivie (credited as Paul Laiken) (script); Larry Lieber (credited) (script)
- Pencils
- Jack Kirby (credited) (layouts); Don Heck (credited) (pencils)
- Inks
- Chic Stone (credited)
- Letters
- Sam Rosen (credited as S. Rosen)
- Genre
- superhero
- Characters
- Avengers [Captain America [Steve Rogers]; Giant-Man [Henry Pym]; Iron Man [Tony Stark]; Thor [Donald Blake]; Wasp [Janet Van Dyne]]; Rick Jones; Teen Brigade; Doctor Svenson; Watcher [Uatu]; Ogor
- Synopsis
- In order to save the Wasp's life, the Avengers seek out the help of Dr. Svenson, only to find he's been replaced by an alien from the planet Kallu.
- Reprints
It is revealed in the letters page that Stan Lee wrote six consecutive pages of the story; likely pages 14-20 as he has often mentioned the speech by the Watcher at the end of the story.