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...