Last Seen Wearing by Colin Dexter
2nd book in the Inspector Morse series. This is one of the most complicated mysteries that I've ever read. Morse & Lewis are brought in to take over a case after the investigating detective died in a car accident. Valerie Taylor has gone missing 3 years ago and presumed dead. But suddenly letters to her parents start arriving to bring fresh interest into the case. Morse immediately assumes she is dead but wonders why letters would start arriving but most of all who would send them. Is it her distraught parents, her mysterious lover or the murderer?
Morse bumbles through the case trying out theories, drinking and listening to opera. One of my favorite scenes is him trying to get into what we would call a stripclub without paying for a ticket. Poor Lewis is left outside to wait. Morse eventually figures it out but then it appears his theory is wrong - but as the book ends we wonder. Maybe he was right after all. You need to read it to judge for yourself.
Morse is one of my favorite book and TV series. So I enjoy going back and re-reading these.