A Vertical Flame Diversion is a chimney that can be found at the back of a cave which is used to stop caves from filling with smoke when a fire has been lit. One can be found in the Mortmain Mountains, in a cave used by both Volunteer Feline Detectives and the Snow Scouts. This particular Vertical Flame Diversion, which has footholes chiseled into one of its sides, also serves as a passageway to the hallway leading to the first Vernacularly Fastened Door. These footholes were discovered by Quigley Quagmire after his reading of Remarkable Phenomena of the Mortmain Mountains.