Arguably one of the most humorous books in Irish literature
called it a "really funny book"), "At Swim-Two-Birds" is both a comedy and an exploration of topics that are hard to describe. One of the most famous Irish novels of all time, along with Joyce's Ulysses
, the novel is about an Irish college student who writes a novel mocking characters in Irish mythology
who come to life to communicate with the author.
Aside from being a great novel, it was also an important one in literary history. It opened up the possibility of reusing or "recycling" fictional characters that have proved successful in other novels. This inspired such other authors as Anthony Burgess. As O'Brien says in the novel's first chapter, "The modern novel should be largely a work of reference. Most authors spend their time saying what has been said before--usually said much better. A wealth of references to existing works would acquaint the reader instantaneously with the nature of each character, would obviate tiresome explanations and would effectively preclude mountebanks, upstarts, thimbleriggers and persons of inferior education from an understanding of contemporary literature." (I suppose you could apply this same rule to E2.)