A killer hunts the members of an old Oxford club—and Sherlock Holmes's brother is the next target

Six months after the bloody return of Jack the Ripper, Sherlock Holmes is starved for entertainment. When a friend of Dr. Watson's suggests a shooting trip in Scotland, Holmes leaps at the invitation. But after nearly a week of dreary Scottish weather, and hardly any shooting at all, Holmes is worse off than before. Watson fears the holiday has been an utter bust—until they are confronted with a murder baffling enough to be worthy of the great detective.

One of the local gentry has been found dead in his library, suffocated in the safe where he kept his most valuable documents. Holmes recognizes the dead man as a member of the same secret society as his brother Mycroft—the Oxford group known as the Seven Sinners. One sinner down, six to go ... but if Mycroft falls, so does England, and Holmes must be quick in order to save both his brother and his country.