An Instance of the Fingerpost, Iain Pears
Historically-set murder mystery. Mystical ending. A rare structure: four manuscripts tell the same story, in sequence, from four different angles. Only the last writer has access to all the other manuscripts. And thus the exciting and unexpected truth is hidden from us until the very end.
The trouble is that it takes a great deal of pain to read through the first three manuscripts. It's as if the author's heart wasn't really in them, but he knew he had to write them to fulfill form. A gruelling read; somewhat rewarding at the end. Some of the historical details (English renaissance) are interesting.