Pale Fire - Vladimir Nabokov

This really is a fiendishly clever novel. It falls into two parts: a long poem entitled Pale Fire by the fictional poet John Shade, and the equally fictional commentary on that poem written by the fictional commentator Charles Kinbote. It quickly becomes clear that, at best, Kinbote is an egomaniac, at worst a delusional lunatic. Does he really have a terrible secret to hide - or is it all in his mind?
In some ways this reminded me strongly of Lemony Snicket's Series of Unfortunate Events in the sheer Gothic strangeness of the Zemblan episodes (Zembla being Kinbote's fictional home country). Pale Fire is a novel of two lives, told in a brilliantly elliptical way, and one that leaves the reader guessing.