Gehenna was the home planet of the Demoniacs.
Gehenna was a newly formed planet (as of the 26th century) and largely consisted of active volcanoes and shifting lava. Smoke from these volcanoes gave the planet a thick atmosphere. The gravity was lighter than on Earth.
Gehenna and its people were named by the human explorers from Earth who discovered it. Life was dangerous on Gehenna, and the Demoniacs spent most of their time simply surviving. Because of this, many chose to leave the planet and to find work on other planets. (PROSE: Mean Streets)
- Gehenna was probably named after the Jewish hell.