Could a woman die of fright alone? And who is the sender of a most grizzly package - two human ears in a box? Holmes and Watson tackle a whole host of new mysteries before Baker Street's most famous detective finally leaves London for the quiet of a Sussex farm.
But one final adventure puts an end to his retirement. As Britain stands poised on the brink of the First World War, can Sherlock Holmes keep a terrible new super-weapon from falling into the enemy's hands?