The Five Orange Pips by Arthur Conan Doyle

A young man seeks Holmes’s help after his family members receive mysterious letters containing five orange pips—each followed by their deaths. As Holmes investigates, he links the case to a dangerous secret society from America. The plot is ominous and atmospheric, with a rare failure for Holmes as justice is served by nature, not man. It’s one of the darkest and most suspenseful of the early Sherlock Holmes cases. Doyle taps into themes of fate and international intrigue.