The stone chamber
On a summers' evening, Robert and Greta Gerdner are shot dead at their isolated home in the Devon countryside. DI Wesley Peterson suspects the execution-style murders might be linked to Robert's past career in the police--until Robert's name is found on a list of people who've been sent tickets anonymously for a tour of Darkhole Grange, a former asylum on Dartmoor. Wesley discovers that others on the list have also died in mysterious circumstance...