Inspector Lastrade drops by Baker Street to socialize and presents Holmes with his current problem. He is baffled by a series of apparently senseless burglaries in which the only thing stolen is a small bust of Napoleon, which is later broken into pieces by the thief. Unlike Lastrade, Holmes sees a sinister purpose behind these irrational break-ins and has that confirmed when a Italian immigrant with Mafia connections is found with his throat slashed at the scene of the latest robbery.