It is the Victorian Era. One woman rules the British Empire; virtually all other women rule domains no larger than their kitchens. The widow of Constable Tobias Hudson is determined not to be one of those other women. She uses the lodgings she has leased at 221B Street to recruit the male figurehead she needs for the consulting detective agency that will make use of her investigative skills and observational abilities. It is a definite plus that the most attractive applicant for that role, Sherlock Holmes, brings with him the level-headed Dr. John Watson. This, then, is the first in the Mrs. Hudson of Baker Street series designed to expose and celebrate the genius and achievements of the true sage of Baker Street.

The services of the consulting detective agency are requested by Lady Parkerton, whose husband, Sir Stanley, appears to have been poisoned after a family dinner in which he had the same food and drink as all other guests. When the family's coachman, who drinks too much and knows too much, is murdered as well, the game is truly afoot. Mrs. Hudson and her colleagues must not only sort through the motives and movements of the Parkerton family and staff, they must contend, as well, with the threat posed by the unexpected return to England of the White Rajah of Sarawak and the sudden intrusion of headhunters into the English countryside.