Baskerville Island

AU. Part of the "Major" series, but can be read alone. John gets a suspicious call from his sister, Harry, and Sherlock discovers that she has programmed a GPS locator to John's phone. That same week, Mycroft asks Sherlock to take a case in the Caribbean, one with modern day rum smugglers. When Sherlock and John are kidnapped, Major and Molly must save them from Baskerville Island.