London, 1930s. As the Industrial Revolution fades into the Great Depression, two sisters embark on an adventure worthy of their father and his late friend, a legendary consulting detective of the Victorian Gaslight Era. The great city is plunged into a new reign of terror by a new master criminal, and Felicity and Charlotte Watson must use their wits and the scientific methods of deduction that have been passed onto them by their predecessors in order to save the millions inhabiting the city and carry on The Legacy of Baker Street.
