# Unity Against a Common Enemy in Invaders from the Infinite

> Theme guide for Invaders from the Infinite by John W. Campbell.

Diverse alien races, including humans, Ortolians, Talsonians, and Venonians, must form alliances to combat the Thessian invaders, highlighting the theme that survival requires cooperation across cultural and interstellar divides.

## Where it surfaces

- [II: Canine People](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/ii-canine-people): The Ortolians seek Earth's help against the Invaders, setting up a potential alliance against a shared threat.
- [III: A Quarter of a Million Light Years](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/iii-a-quarter-of-a-million-light-years): Earth and the Ortolians must unite to face the Thessian threat, with potential alliance with the Sirians.
- [V: Ortol](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/v-ortol): The terrestrians and Ortolians work together to defend Ortol from the Thessian attack.
- [World 3769–37,478,326,894,6, Talso](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/vii-world-3769-37-478-326-894-6-talso): The crew of the Ancient Mariner and the Talsonians form an alliance against the Thessians, pooling their unique strengths.
- [VIII: Undefeatable or Uncontrollable?](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/viii-undefeatable-or-uncontrollable): The terrestrials and Talsonians cooperate to share power and knowledge in the fight against the Thessians.
- [X: Improvements and Calculations](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/x-improvements-and-calculations): Earth, Talso, and Ortol ally against the Thessian threat, with Arcot sharing knowledge and resources to strengthen the coalition.
- [Write Off the Magnet](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/xi-write-off-the-magnet): The terrestrial squadron follows Arcot's orders despite heavy losses, showing coordinated resistance against the Thessian threat.
- [XII: Sirius](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/xii-sirius): Arcot forges an alliance with the Sirians, Ortolians, and Talsonians to combat the Thessian threat from Thett.
- [Home Again](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/xvi-home-again): Torlos brings a Nansalian fleet to aid Earth, demonstrating solidarity across galaxies against the Thessian invasion.
- [Earth's Defenses](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/xviii-earth-s-defenses): Earth's fleet, Ortolians, Talsonians, and the human crew unite to defend against the Thessian invasion, highlighting cooperation across species and worlds.
- [XIX: The Battle of Earth](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/xix-the-battle-of-earth): The Solarian forces unite under Arcot's command, trusting his plan despite the dire situation, highlighting collective action against the Thessian threat.
- [XX: Destruction](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/xx-destruction): The alliance of Earth, Ortol, and Talso works together to locate and confront Thett's forces, highlighting cooperation against a shared threat.
- [XXI: The Power of the Thought](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/xxi-the-power-of-the-thought): The Talso forces and their allies unite to resist the Thessian invasion, though their defenses ultimately fail.
- [XXV: With Galaxies in the Balance](https://www.betterreads.dev/discover/invaders_from_the_infinite_se/chapters/xxv-with-galaxies-in-the-balance): The crew works together to repair the ship and plan the attack, while the Thessians coordinate their defenses under the Sthanto's command.

## Links

- HTML: https://www.betterreads.dev/discover/invaders_from_the_infinite_se/themes/unity_against_a_common_enemy
- Themes index: https://www.betterreads.dev/discover/invaders_from_the_infinite_se/themes