Hugh Kenner is thought to have once asked rhetorically about O'Brien, "Was it the drink was his ruin, for ruin is the word. So much promise has seldom accomplished so little." At the end, "a great future lay behind him."
Perhaps, but taken in whole, O'Brien's novels and newspaper columns, whether written in Gaelic or English—all now in print thanks to the Dalkey Archive—have given him a cult status unmatched by any other Irish writer. Among his legion of fans are James Joyce (who O'Brien often parodied), Samuel Beckett, Graham Greene (who first recommended At Swim-Two-Birds to its British publisher), John Updike, Seamus Heaney (who called At Swim "hilarious and melancholy"), and Roy Blount, Jr. And, oh yes, Dylan Thomas, whose praise for At Swim-Two-Birds is perhaps the most fitting: "Just the book to give to your sister, if she is a dirty, boozey girl."
Only a fool would attempt to describe the plot of At Swim-Two-Birds. Here I go: The title is a literal translation from the Gaelic of ... well, never mind, you wouldn't make sense of it anyway (I certainly couldn't), but it's a ford on the River Shannon said to be visited by the legendary king, Mad Sweeney, who was exiled from his homeland after the Battle of Moira in 637 (see Seamus Heaney's magnificent 1983 translation, Sweeny Astray) and resurrected by O'Brien as a character in his novel.
Still with me? A narrator, a student of Irish literature unnamed by O'Brien, lives with his uncle and has a dream job for an Irishman: He works in a Guinness brewery. He establishes his creed as a writer at the outset: "One beginning and one ending for a book was a thing I did not agree with."
The narrator is a lazy sod who can't seem to finish his book, control his characters, or tie all the strands of his book together. One of those plot streams involves Dermot Trellis, a writer of pulp westerns. Trellis's characters rebel against their creator; wanting control over their own lives, they drug him to make him sleep so much he can't write his book. But Trellis fights off slumber long enough to bring a female character, Sheila Lamont, into existence; she becomes real, or at least real enough to bear his child ("blinded by her beauty"—i.e. of his own fictional creation—Trellis loses control and assaults her).
In time, Orlick is born, inheriting his father's—and presumably the unnamed narrator's and Flann O'Brien's—gift for writing fiction. Orlick writes a novel in which all of Trellis's creations put Trellis on trial and punish him for daring to manipulate him. But, as he is about to be executed, Trellis's creator, the student, unexpectedly passes his exams with flying colors and ...
I don't want to spoil it for you. Actually, I'm not sure that I have all this down correctly, though I've read three separate copies, annotating them all. I'm also still not sure exactly how the two American cowboys appear or why the mythical Irish hero Finn McCool jumps in (or whether he is Sheila Lamont's father) or what part the Pooka (a species of human Irish devil endowed with magical powers) named Fergus MacPhellimey plays. (But I can testify that an invisible good fairy who lives in MacPhellimey's pocket appears at opportune times to counter the Pooka's evil.) Part of the problem is keeping track of the three major intertwined plot threads; an even larger problem is recovering one's concentration after laughing out loud at nearly every page.
Thankfully, you don't have to get all the jokes in order to laugh at them. As V.S. Pritchett wrote, "In O'Brien, the object is a box that contains a box containing boxes getting infinitely smaller, until they are invisible." He might have added that each box contains a joke funnier than the last, though the punch lines are sometimes in Gaelic.