Arthur Conan Doyle's 'The Sign of the Four' plunges Sherlock Holmes and Dr. Watson into a complex web of deceit, murder, and hidden treasure. The adventure begins when Mary Morstan seeks their help regarding a mysterious pearl and an annual anonymous gift. This leads them on a thrilling chase through London's underworld, unraveling a dark history involving colonial India, a priceless hoard of jewels, and four former convicts bound by a shared secret. Holmes's brilliant deductive reasoning is put to the ultimate test as he navigates treachery, betrayal, and a dramatic boat pursuit, ultimately exposing the truth behind a long-lost fortune and a sinister pact.