The House on the Borderland is unique in several ways. The narrative itself is a double-frame narrative: the editor of the volume is presenting a manuscript he found under mysterious circumstances, describing the account of two fishermen who themselves discovered a hand-written account of the cosmic haunting of a recluse’s remote home.
Additionally, the novel is one of the earliest examples of the departure of horror fiction from the Gothic style of supernatural, psychological hauntings, to more realist, science-fiction/cosmic horror themes. The recluse is, among other events, transported to a mysterious supra-universal plane populated by monsters and elder gods; and his house withstands assaults from legions of monsters as he travels across time and the solar system.
The book was very influential on Lovecraft, who himself was famous for the cosmic horror themes in his work. The concept of an uncaring, and even evil, universe that Lovecraft found so disturbing is front and center in this supremely strange novel.