Deep in the Yorkshire Dales, the body of the famous spelunker Dave Atkin is found—and everything points to murder. Detective Oldroyd and his assistant from London, Officer Carter, begin the investigation, but they face a multitude of mysteries. How did the body end up so deep in a cave, if the dead man had no equipment for descending? As the investigation develops, more and more secrets and lies come to light, and it seems that the mystery of this little town is darker and more tangled than even the deepest caves.