Missing on Dartmoor

Mary Cranson had done the walk many times before, but now had simply vanished from Dartmoor near the prominent landmark called Haytor. Her boyfriend raises the alarm when she doesn’t meet him as arranged in the local pub. 
For the investigating officer, Detective Inspector Richard King, the intriguing aspect is that many of her friends knew she would be on the moor as she had told them of her intentions the previous evening. King and his small team of detectives begin the arduous task of interviewing the people who would have known her whereabouts that fateful afternoon. Could she have been consumed by one of the notorious bogs on the moor or is the reason for her disappearance something more sinister? 
The detectives are also dealing with thefts of vehicles and machinery, mainly from farms across Dartmoor. These have continued undetected for over six months and questions are being asked in the local media about the lack of progress in catching the thieves. The profile of these cases increases significantly when a theft goes disastrously wrong.  
King is also made aware of a barn fire close to Haytor, but is this connected to the other cases? Pressure is mounting on the wily detective from the chief constable who wants progress on both the thefts and the missing woman.