Based on Arthur Conan Doyle's works "Engineer's Thumb," "Second Stain", "Bruce-Partington Plans" and "His Last Bow." The brilliant detective Sherlock Holmes and his faithful friend Dr. Watson again unravel the crimes, even though they seemed to have other priorities now. Holmes has appeared apiary, and Watson has become a family man, departed from risky business. However, the loss of important documents for the United Kingdom, the machinations of secret agents, convoluted murders and accidents do not let detectives retire.