The Way Through the Woods by Colin Dexter
They called her the Swedish Maiden - the beautiful young tourist who disappeared on a hot summer's day somewhere in North Oxford. Twelve months later the case remained unsolved - pending further developments - at Thames Valley CID. On holiday in Lyme Regis, Chief Inspector Morse is startled to read a tantalizing article in The Times about the missing woman. An article which lures him back to Wytham Woods near Oxford...and straight into the most extraordinary murder investigation of his career.