"Black Peter" is a story from "The Return of Sherlock Holmes" by Arthur Conan Doyle. In this gripping tale, Sherlock Holmes, the brilliant detective, is called upon to investigate the brutal murder of Captain Peter Carey, a notorious and violent former sea captain known as "Black Peter." Carey's body is discovered impaled by a harpoon in his cabin, which is locked from the inside, presenting a baffling mystery. Holmes is enlisted by Inspector Stanley Hopkins of Scotland Yard, who is eager to learn from the great detective. Holmes and his loyal companion, Dr. John Watson, delve into the case, uncovering a web of secrets and deceit. They discover that Carey had many enemies and that his violent temper had made him a feared and hated man. As Holmes investigates, he identifies several suspects, including a young seaman named Patrick Cairns, and a broker named Neligan, whose father had been ruined by Carey.