Why did Helen Stoner visit Holmes?

Helen Stoner comes to Holmes at Baker Street “in a pitiable state of agitation…with restless, frightened eyes, like those of some hunted animal.” She, like most of Mr. Holmes’s visitors, has a mystery to be solved—one that threatens her life.

Her stepfather, Dr. Roylott, was the last heir of a once great and wealthy family, though the ancestral fortune had fallen away over the years, leaving nothing but a grand manor on a small plot...

Helen Stoner comes to Holmes at Baker Street “in a pitiable state of agitation…with restless, frightened eyes, like those of some hunted animal.” She, like most of Mr. Holmes’s visitors, has a mystery to be solved—one that threatens her life.

Her stepfather, Dr. Roylott, was the last heir of a once great and wealthy family, though the ancestral fortune had fallen away over the years, leaving nothing but a grand manor on a small plot of land. Ms. Stoner’s mother contributed a considerable sum of money each month to the family fortune, with the agreement that both Helen and her twin sister Julia would come into a portion of these savings upon their marriage. Two years before Helen comes to see Mr. Holmes, Julia became engaged to be married, and yet, not two weeks after she informed her stepfather, she was killed.

Helen was awoken one night by her sister’s screams, and running to Julia’s bedroom she found her sister in a terrible state; her sister’s last words were, in shock, “’It was the band! The speckled band!’” Helen believes her sister to have died of fright, but of what frightened her she hasn’t the faintest clue. She does, however, believe that her stepfather had something to do with it—that he had her twin killed rather than give her her due money upon her marriage. Dr. Roylott has an intense reputation for violence in the community, and Helen speaks at length of this in her explanation to Holmes and Watson. He had beaten his butler to death in Calcutta, narrowly avoiding a murder charge but serving time for the crime; in England, she asserts that he lashed out regularly, “’until at last he became the terror of the village…for he is…absolutely uncontrollable in his anger.’”

Now Helen herself is engaged to be married, and due to a renovation of the manor has had to move into her sister’s old bedroom. In addition, she has begun hearing a low whistle in the night, a noise that her sister had heard for several nights before her death. So Helen has come with this set of clues to Baker Street, in hopes that Holmes can solve the mystery of Julia’s death, and protect herself from falling victim to the same fate.