The Way Through the Woods by Colin Dexter
Quietly, rather movingly, Strange was making his plea: 'Christ knows why, Lewis, but Morse will always put himself out for you.' As he put the phone down, Lewis knew that Strange had been right... in the case of the Swedish Maiden, the pair of them were in business again... 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. 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.