The Primordial Core's an unconquerable dungeon, the lair of the most powerful monster ever to exist, the Original Monster, the incarnation of evil—Swallow... who happens to be a lazy boss monster who just wants to sleep. Taking care of this lazy bum is Renee, a homunculus maid whose obsession with Swallow knows no bounds. At this point, the only one keeping the dungeon running is Patrick, the last brain cell of the bunch—and he's a skeleton! Will Mr. Swallow get any rest amid all this chaos?