The story involves a married couple, Paul and Elizabeth, renting a house (the Carpenter's Gothic of the title) from a mysterious divorced geologist. Paul, who once ran some shady business dealings for Elizabeth's late father, is trying to get started as the media consultant for a southern evangelist while Elizabeth wanders and frets around the house. The action never leaves the house and mainly follows Elizabeth as other characters come and go. Gaddis' genius (for me) is in the dialogue. Ninety percent of the writing is dialogue--the fragmented, digressive speech of a hyperkinetic group of characters. Characters ramble on for paragraphs, changing direction in mid-sentence, jumping to phone conversations without warning and occasionally Gaddis will even insert a stage direction without separation into the midst of a chunk of dialogue.
And it all works brilliantly. Gaddis has captured the feverish way people talk to each other, especially those closest to us who don't ever seem to require context. He also manages to touch on subjects like Christianity, colonialism (and the relationship between the two), sexuality, politics--all without ever leaving the confines of the carpenter gothic house in suburban New York.