Sherlock Holmes and Doctor Watson are searching for the fifth Earl of Convarran who disappeared after returning to England following a disastrous excavation at the Black Pyramid in Dashoor, Egypt. During his investigation, Holmes discovers his clients are concealing a deadly secret, a secret that entangles him and Watson in a conspiracy that threatens all their lives. At the heart of the mystery are two ancient artifacts. Relentlessly pursued by cultists, collectors, and the British govern...