A scarab-shaped clue, a parchment, and a cipher written in symbols instead of letters
On a South Carolina island, a narrator and his friend William Legrand find a strange parchment that seems blank — until held near heat, revealing a row of mysterious symbols and a cryptic reference to a 'death's-head' and a 'bishop's hostel.' Legrand is convinced the symbols are a cipher hiding instructions to a pirate's buried treasure. With no key and only the parchment itself, how can anyone crack a code they've never seen before?
Reveal the answer
Legrand cracks it by counting which symbol appears most often and guessing it stands for 'e', the most common letter in English — then works out the rest from common short words and letter patterns, eventually decoding the full route to Captain Kidd's gold. Edgar Allan Poe's 'The Gold-Bug' (1843) is credited with popularizing cryptanalysis and letter-frequency analysis for a mass audience, decades before it became a staple of detective fiction.