Of the 3,816,483 citizens of London in 1881, a dozen are fated to die at the hands of the 'Twelve Caesars' kill. Sherlock Holmes and his reluctant partner Dr. John Watson have deduced the method and means of the crime, but not the madman responsible! While both Watson and the Metropolitan Police lose patience with Holmes and his eccentricities, the young sleuth goes missing to help an old friend!