S. is a book that is pretty complicated to read. It was originally a gift for my wife (who loves to read very much) but she found it difficult to read a second time. Basically this book should be taken step by step, reading the book first, followed by reading through the notes by the first reader, then reading the notes of the second reader while sifting though inserts that the two readers wrote on as they tried to figure out and piece together the mystery unfolding before them. Confused? Me, too.