http://www.goodreads.com/book/show/960146.Days_With_Diam_Or

Svend Age Madsen, born in 1939, stands today as one of Denmark's most important experimental novelists. Concerned with the unstable or illusory nature of reality, he is a master of the fantastic, skirting around realism, but never entirely realistic. For him, time, place, human nature are all indeterminate concepts, all tending to dissolve and re-emerge elsewhere in a different form. In Days with Diam the manifold and complex nature of human personality results in the creation of a world in which the doppelganger motif is related to Mendel's laws of segregation: the narrator meets himself in various guises, even sees himself through the window writing an account which, when he finally gains access to it, turns out to be in his own handwriting. Who is this narrator? And what is this Diam who appears in an array of guises ranging from the prudish to the lascivious? A figment of the imagination, perhaps - but of whose imagination? And what is the implication of the character without a story? In one chapter, Svend Age Madsen explains the system behind the book - but is this the whole key to its understanding?