Dr James Earle and his wife live in comfortable seclusion near the Hog's Back, in the Surrey countryside. When Dr Earle disappears, Inspector French is called in to investigate. At first he suspects a simple domestic intrigue, but the case soon takes a more complex turn. Other people also vanish mysteriously, but if they have been murdered, what can be the motive? This fiendishly complicated puzzle is one that only the inspector can solve.