London, 1930s. As the glory of the Industrial Revolution has faded into memory replaced by the struggles of the Great Slump, London is vulnerable. A master criminal is about to plunge The Big Smoke into a new reign of terror. Two sisters embark on an adventure worthy of their father and his late friend, a legendary consulting detective of the Victorian Gaslit Era. Charlotte and Felicity Watson must be ready to battle with their wits, the scientific method of deduction, and their fists to save the millions inhabiting London. Join these new heroes as they show the world what they are capable of and carry on The Legacy of Baker Street.