Major Doctor Ghastly's latest version of a world-domination device is The Almighty Stink Ray, with which Con Carne threatens to stink up the entire world unless he is given a huge ransom and small piece of land in Montana. Cod Commando, the only soldier without a nose, is sent to destroy the Almighty Stink Ray. Billy wanders into a junkyard, where a massive hole in the earth opens up and pulls him down in. Later, Mandy and Grim get pulled in as well. They land at the center of the Earth, which is home of Nergal, a devilish creature. The lonely Nergal, who has been watching Billy and Mandy for some time, wants Grim to hand over the kids to him so they can be his friends forever. Grim happily leaves the kids behind as he returns to the surface; however, he later goes back for them because he can't handle the guilt of abandoning his friends. In the end, Grim is defeated by Nergal's electrified tentacles, but Mandy defeats Nergal merely by kicking him in the shin.