Craziest novel I've ever read. First published in 1939, it's on Time Magazine's list of 100 greatest novels. My Penguin edition refers to it as an "experimental blend of satire, fantasy and farce."
On the back cover are blurbs from James Joyce and Dylan Thomas. The latter says, "This is just the book to give your sister if she's a loud, dirty, boozy girl."
The central character, Dermot Trellis, is an Irish lout who spends most of his time in bed. He is writing a tale in which "there will be no hero, nothing but villains." Celebrating the "birth" of one of his characters, he informs the press that credit is due in part to another author, William Tracy, a writer of Westerns.
Soon several other Tracy-inspired characters appear, cowpunchers brandishing shooting-irons on the streets of Dublin. They fall in with some characters from Irish mythology, including Finn MacCool, mad King Sweeney, a type of devil called a Pooka, and a Good Fairy.
Events in Trellis's life are interspersed with extracts from the story he's writing. The extracts grow longer, and the characters become fractious after the author seduces one of them and brings into existence "offspring of the quasi-illusory type." Eventually they drug Trellis, beat the crap out of him, and take control of the novel.
The writing is humorous, erudite, and fey. The vocabulary is prodigious, and there are snippets of Latin, Greek, and Irish Gaelic. The narrative is destabilized by intentionally bad poetry and many authorial asides, including synopses for "the benefit of new readers."
As one character explains, "It's the sort of queer stuff they look for in a story nowadays."