Sherlock Holmes

Violet Smith has recently started a new job as music teacher to Robert Carruthers, staying during the week at his house in the country. She consults Holmes because she is worried about being followed once a week on her way to the railway station by a man on a bicycle. Carruthers asks Miss Smith to marry him, but Holmes sees a sinister connection between him and the stalker.

Holmes is approached by Helen Stoner, who feels threatened by her domineering step-father, Dr Grimesby Roylott. Her sister died mysteriously just before her planned wedding, and Helen has heard again the curious whistle she first heard on the night of her sister's death.Holmes perceives great danger and lays a complicated plan to defeat the threat to the beautiful Helen.

A plumber, John Horner, is arrested just before Christmas and charged with stealing a famous jewel, the Blue Carbuncle, from Lady Morcar. He denies the theft - but he has a criminal record, and all the evidence is against him. After Holmes's doorman finds the Carbuncle in a Christmas goose, Holmes uses an old hat to track the goose to a poultry dealer, then traps the servant who stole the jewel and framed the plumber. The Blue Carbuncle has a dark history, and the stone features in the programme's opening credits with turbulent scenes from its past.