The film's frame story, and the narrative it returns to the most, concerns a submarine crew transporting a volatile substance that will explode if they ever resurface. As the crew struggle to survive with low oxygen levels, a Lumberjack (Roy Dupuis) mysteriously forces his way onto the vessel; the crew believe his sudden appearance may lead to an escape from their predicament. The men navigate a labyrinth of rooms and passageways while trying to access the captain's chamber. Along the way, they recount stories that lead to other stories, which unfold in a complex and layered manner. The most important of these "sub-stories" shows the woodsman and his fellow "sapling-jacks" trying to rescue a woman named Margot from depraved kidnappers. Other sub-stories involve: a surgeon kidnapped by a team of "women skeletons" who work as Insurance fraud; a madman on a train under the charge of a womanizing psychiatrist; a mustache that seeks to comfort the widow of the man whose face it used to adorn; and a doctor cursed by a bust of Janus. The submarine crew finally reach the captain's "forbidden room", only to find him incapacitated. Most of the men die of asphyxiation, but the woodsman finds that the volatile cargo has transformed into his love, Margot. A passionate kiss leads into a montage of proposed endings from "The Book of Climaxes", and an abrupt, inconclusive ending to the film itself.