The House on the Borderland

A fantasy/horror novel by William Hope Hodgson, who also created Carnacki, the Ghost-Finder and The Night Land. It was first published in 1908. HP Lovecraft said "but for a few touches of commonplace sentimentality [it] would be a classic of the first water."

Some friends visiting Ireland find the curious ruins of the eponymous house, and an old diary of the man who was presumably the last inhabitant of it. The majority of the story is the contents of the diary.

Here's a link to an online version of the entire novel at Project Gutenberg. It comes in several formats, including HTML, EPUB, Kindle, and TXT.

Was adapted in The Noughties as a one-volume Graphic Novel by Vertigo Comics, with Richard Corben on drawing duties.

Tropes used in The House on the Borderland include:

All There in the Manual:
- A possible explanation for who the Swine Things were and what they wanted can be found in Hodgson's Carnacki story, The Hog. It really depends on whether they're set in the same continuity or if Hodgson was simply reusing a concept. That said, the Mind Screw doesn't completely go away because The Hog does nothing to explain the House itself or its green doppleganger.
- The name of the framing story's narrator ("Mr. Bereggnogg") isn't revealed anywhere in the book except the title page, which a lot of readers would typically skip.
  - At least one edition of the book doesn't include that title page, leaving "Bereggnogg" completely unidentified.
Apocalyptic Log: The diary.
Apocalypse How
A Boy and His X: A man and his dog.
Brother-Sister Incest: Incestual context was added to the graphic novel, which displeased some fans of the original book.
Cool Old Guy: The Recluse, at least when he's protecting the house and driving away the Swine Things
Cosmic Horror Story: A precursor, in any case.
Covers Always Lie: The house (before being mostly destroyed) is a castle-like place perched, when Berreggnogg and Tonnison find it, on a jutting cliff over a chasm and waterfall in a spooky forest in western Ireland. So one edition got a cover picture of a farmhouse, with barn and silo, surrounded by parched brown soil and a single tree ... and a partially shucked ear of maize in the foreground implying that the setting is in North America. Zigzagged, because most covers for this tale are rather closer to the true version.
Eldritch Location
Framing Device
Genre Shift: Subverted. It starts out as Cosmic Horror, then quickly turns into a mix between Action-Horror and Mystery but then goes right back to Cosmic Horror in the second half.
Haunted House
Heroic Dog: Pepper.
Mind Screw
No Ending - Yes, in the sense that 1. we never get any explanations on the Swine Things or any of the other supernatural stuff, and 2. we aren't given the details about what actually became of the Recluse and his sister. However, the Framing Device's epilogue does give the horrifying broadstrokes of what ultimately happened after the diary's narrative is cut off (while leaving the particulars to the imagination).
No Name Given: The diary's author.
Pig Men
Posthumous Character: The Recluse's lover.
Thematic Series: This book is the second installment of what Hodgson referred to as a trilogy. None of the three books share the same characters. In terms of plot and setting, the first and third books in this trilogy - The Boats of the "Glen Carrig" and The Ghost Pirates, respectively - don't have all that much in common with each other and have even less in common with House.
Things That Go Bump in the Night
Unreliable Narrator: It's possible to intepret everything as delusions brought on by the Recluse's excessive grief and possible dementia (his sister seeming to not be aware of any of the supernatural stuff certainly supports this notion). That viewpoint holds up until the epilogue when Tonnison and Bereggnogg discover that the events in the diary probably did happen.