In Sir Arthur Conan Doyle's short story "The Adventure of the Speckled Band," Helen Stoner appears at 221B Baker Street very early on an April morning in 1883 seeking help from Sherlock Holmes. Miss Stoner tells Holmes that she fears that her life might be in danger from her stepfather, Dr. Grimesby Roylott.

In due time, Miss Stoner relates her concerns to Holmes and Watson, including details about the death of her twin sister, Julia, two years ago.

Holmes has some concerns about Miss Stoner's story about her sister's death, mainly regarding a whistling sound.

"As I opened my door I seemed to hear a low whistle, such as my sister described, and a few moments later a clanging sound, as if a mass of metal had fallen...."

“One moment,” said Holmes, “are you sure about this whistle and metallic sound? Could you swear to it?”

“That was what the county coroner asked me at the inquiry. It is my strong impression that I heard it, and yet, among the crash of the gale and the creaking of an old house, I may possibly have been deceived.”

Holmes also inquired about a "speckled band" that Miss Stoner mentioned.

"[A]s I bent over her she suddenly shrieked out in a voice which I shall never forget, ‘Oh, my God! Helen! It was the band! The speckled band!’"

“Ah, and what did you gather from this allusion to a band—a speckled band?”

“Sometimes I have thought that it was merely the wild talk of delirium, sometimes that it may have referred to some band of people, perhaps to these very gipsies in the plantation. I do not know whether the spotted handkerchiefs which so many of them wear over their heads might have suggested the strange adjective which she used.”

Holmes shook his head like a man who is far from being satisfied.

When Miss Stoner had finished her story and answered Holmes's questions about it, Holmes expressed another concern, bordering on suspicion.

“You have done wisely,” said my friend. “But have you told me all?”

“Yes, all.”

“Miss Roylott, you have not. You are screening your stepfather.”

“Why, what do you mean?”

For answer Holmes pushed back the frill of black lace which fringed the hand that lay upon our visitor's knee. Five little livid spots, the marks of four fingers and a thumb, were printed upon the white wrist.

“You have been cruelly used,” said Holmes.

The lady coloured deeply and covered over her injured wrist. “He is a hard man,” she said, “and perhaps he hardly knows his own strength.”

There was a long silence, during which Holmes leaned his chin upon his hands and stared into the crackling fire.

Holmes might be thinking back to Miss Stoner's answer to an earlier question and thinking that she might not be entirely forthcoming regarding certain aspects of Dr. Roylott's behavior toward her.

"She [her sister, Julia] smiled back at me, closed my door, and a few moments later I heard her key turn in the lock.”

“Indeed,” said Holmes. “Was it your custom always to lock yourselves in at night?”

“Always.”

“And why?”

“I think that I mentioned to you that the doctor kept a cheetah and a baboon. We had no feeling of security unless our doors were locked.”

“Quite so. Pray proceed with your statement.”

Holmes's suspicions prove to be well founded when an angry, fireplace-poker-bending, self-proclaimed "dangerous man to fall foul of" Dr. Grimesby Roylott appears in Holme's consultation room threatening Holmes with bodily harm if he dares to meddle in his affairs.