In Klingon mythology, Gre'thor is where the dishonored go when they die. The souls of the honorless are ferried across an ocean of blood to Gre'thor on the Barge of the Dead. Gre'thor is guarded by the beast Fek'lhr, and is home to the Fek'Ihri. It's counterpart is Sto-vo-kor, the rough equivalent of heaven in Klingon mythology.
- “Afterlife”: The player is commanded by Emperor Kahless to travel to Gre'thor to seek out the dreaded tyrant Molor and stop the Fek'Ihri invasion of the empire.
- “Leap of Faith”: The player goes to Gre'thor on the search for the soul of L'Rell. After defeating Fek'lhr in his lair, Gowron offers his soul in exchange for L'Rell's before J'Ula could finish offering hers, saying that he would rather be in the company of fellow Klingons in Gre'thor than remain alone in the void. Fek'lhr eventually accepts J'Ula's new bargain of J'mpok's and Aakar's souls in exchange for Gowron's freedom.
- “A Day Long Remembered”: During the final battle of Qo'noS, Aakar is killed by the player and J'Ula defeats J'mpok in single combat, paving the way for L'Rell to assume the Chancellorship. With both Aakar and J'mpok dead and banished to Gre'thor as promised, Martok remarks that he is pleased that Gowron is released and had gone to Sto-vo-kor, something he assumes Fek'lhr to be glad to be rid off.
- “The Gates of Gre'thor”: The player is commanded by Emperor Kahless to travel to Gre'thor to seek out the dreaded tyrant Molor and stop the Fek'Ihri invasion of the empire. (this mission was folded into Afterlife)
|Details||Fek'Ihri Horde • Fek'Ihri • Gre'thor|
|Ground Forces||Tortured Soul (ground) • Hordling • Enslaved Hordling • Ravager • Slave Master • Chieftain|
|Starships||Tortured Soul (space) • S'Kul Fighter • Fer'Jai Frigate • K'Norr Escort • Kar'Fi Battle Carrier (Mob) • Drek'Hi Dreadnought|
|NPCs||D'Jar • Fek'Ihri Horde Leader • Fek'lhr • Herron • Molor • Spectre of Cowardice • Spectre of Dishonor • Spectre of Treachery • V'Zmar|
|NPC starships||Dragan • Fektour • Mn'ek • Penkrr • T'merek|