War of the Netherworld, Part 1 is the twelfth episode of Disgaea: Hour of Darkness.
The Earth Defense Force (EDF) armada appears in the 'Stellar Graveyard II', entering into the Netherworld through the same path Gordon, Jennifer and Thursday used. Upon meeting the EDF, Gordon cheers in delight, but Jennifer knows deep in her heart that they were just used. Gordon gets angry with her, and dismisses her. Immediately after that, an EDF soldier says that Gordon is to be executed, and attacks. After the battle, General Carter taunts Gordon through a hologram. Carter promises to tell the people of earth that Gordon died valiantly while fighting the overlord, and laughs evilly before cutting the transmission. Laharl and Etna wonder if they should recruit Carter, as he seems like a decently evil human. Flonne yells at them for joking like that. Jennifer is hurt by Gordon's dismissal, and Gordon feels guilty for trusting the EDF rather than her.
Later on, Kurtis appears, and at first had intended on settling things with Gordon, but instead is ashamed to even call Gordon his rival, considering that Gordon lost to the Overlord. When Gordon yells about how the true villain is "right before his very eyes" (aka Kurtis), Kurtis asks Gordon to prove him wrong, and summons a bunch of soldiers before running off.
Deeper into the Stellar Graveyard II, we see Vulcanus laughing about how the humans will destroy all the demons, and then once Vulcanus kills The Seraph, then he will be the god of all. Flonne senses a dark and evil presence at this point, leaving everyone to wonder if she is just imagining things.
In the final area of the Stellar Graveyard II, Jennifer is still showing signs of depression. With Gordon unable to come out with an apology, Jennifer continues to blame herself for everything that has transpired… Laharl suddenly senses someone. Kurtis pops out, commending the Overlord for sensing him, while Laharl commends him for having gotten so close without being detected. Kurtis then challenges Laharl to a battle. After the battle, Laharl wonders why Kurtis his holding back. Kurtis reveals that he doesn't wish to injure the 'VIP' (to which Flonne comes to the conclusion that Kurtis fell in love with her). The Space Battleship Gargantua appears over the group, and Kurtis takes Jennifer, telling her that General Carter wants her brought back to the ship alive. Jennifer depressingly goes along. Gordon stops them both, telling Jennifer that she can't go, asking Jennifer if she believes what she is doing is right. When Jennifer hesitates, Kurtis knocks her out, and carries her unconscious body, telling Gordon and the group that if they want Jennifer back, they must come aboard the Gargantua to get her. He then flies off, ending the chapter.
There are no special endings for this chapter.