married at the time that she died.  Now, Helen is engaged to be married and fears that she, too, will be killed.

Helen, herself, does not say that she suspects her stepfather.  However, she does talk about how violent he is and she reluctantly shows Holmes marks on her wrist where he has grabbed her.  She fears that she will be killed, though, because Roylott has recently had her move into the room where her sister died.  She has also heard strange sounds that her sister reported hearing soon before her death.  Therefore, she worries that she will die just as her sister did.  She does not specifically say that she suspects that her stepfather will kill her, but it seems clear that she is at least subconsciously aware that he might be a danger to her.  This is why she comes to see Holmes.

Helen Stoner has recently been sleeping in the bedroom right next to her stepfather's. This was her sister Julia's room at the time she died under mysterious circumstances. Helen has recently become engaged. Her sister became engaged shortly before she died. Helen hears the same low whistling her sister described to her one night.

“‘Tell me, Helen,’ said she, ‘have you ever heard anyone whistle in the dead of the night? .... Because during the last few nights I have always, about three in the morning, heard a low, clear whistle. I am a light sleeper, and it has awakened me. I cannot tell where it came from—perhaps from the next room, perhaps from the lawn. I thought that I would just ask you whether you had heard it.’"

These are three ways in which Helen Stoner's situation when she visits Sherlock Holmes are similar to Julia's just before she died. Helen is engaged, she is sleeping in the same bedroom, and she has heard the same whistle. It is the whistle that alarms her because it reminds her of what Julia had told her about it earlier. Because of that whistle she waits until daybreak and then hurries to London by dog cart and train to consult Sherlock Holmes. She had gotten his name and address from a friend named Mrs. Farintosh whom the detective had assisted in retrieving a piece of valuable jewelry.

Another thing that Helen and Julia have in common, although this is not found out until much later in the story, is that their stepfather Dr. Grimesby Roylott murdered Julia and plans to murder Helen. The half-mad doctor has thought of sending a poisonous snake through the ventilator into the next-door bedroom, but he can't be sure it will bite the sleeping girl on any given night. He has to have a way of summoning it back up the bell-rope and through the ventilator. So he has trained it to respond to a low whistle which he blows at around three o'clock in the morning while the intended victim is still presumably asleep.

It so happens that Helen is not asleep on the morning she hears the whistle.

Imagine, then, my thrill of terror when last night, as I lay awake, thinking over her terrible fate, I suddenly heard in the silence of the night the low whistle which had been the herald of her own death.

Apparently the only flaw in Dr. Roylott's sinister plan to commit a second perfect crime of murder was the fact that he was forced to blow a whistle at around three o'clock in the morning. When Holmes and Watson are hiding in Helen's bedroom at Stoke Moran, they hear that same whistle, and it leads to Dr. Roylott's death as well as to the solution of the murder of Julia Stoner two years earlier.

Helen Stoner comes to see Sherlock Holmes because she is terrified. She thinks someone may be trying to kill her, just as someone killed her twin sister Julia two years before. Sherlock Holmes and Dr. Watson meet with her in the waiting room on the ground floor at 221B Baker Street. Holmes tries to soothe her obvious agitation and urges her to sit closer to the fireplace because she is shivering.

"Pray draw up to it, and I shall order you a cup of hot coffee, for I observe that you are shivering.”

“It is not cold which makes me shiver,” said the woman in a low voice, changing her seat as requested.

“What, then?”

“It is fear, Mr. Holmes. It is terror.” She raised her veil as she spoke, and we could see that she was indeed in a pitiable state of agitation, her face all drawn and grey, with restless frightened eyes, like those of some hunted animal. 

Holmes takes her case because of her "pitiable state of agitation." She tells him she does not have any money to pay his fee. Holmes often works on a "pro bono" basis if a case intrigues him or if he feels sympathy for the client.

Helen tells him a long back story involving her violent stepfather. Her sister Julia died of unknown causes two years ago. Before her death she had told Helen she had been hearing a strange, low whistle at around three in the morning for the past few days. Dr. Roylott has now forced Helen to move into Julia's former bedroom, directly adjacent to his, by ordering some apparently unnecessary repairs to Helen's own room farther down the corridor. The first night Helen slept in Julia's bed she heard the strange, low whistle her sister had described. This is what has frightened her so badly. She was already upset about having to sleep in her sister's room and in her sister's bed. She came directly to see Sherlock Holmes as soon as it grew light.

Among all the other details she tells Holmes in her back story are the important facts that Julia was engaged to be married when she died and now Helen is engaged to be married within one or two months. It seems pretty obvious that Dr. Roylott would like to see his stepdaughters dead, because he is desperate for money and is legally obligated to pay either girl one-third of the income from their deceased mother's estate each year if and when she marries. But the biggest questions are: How could anyone have killed Julia when she was sleeping in a room with the door locked and the window covered by a bolted iron shutter? And how could anybody get to Helen in that same locked room?

The most important event was the death of Helen Stoner's twin sister two years earlier. It is still vividly imprinted on Helen's mind, especially because the mystery of Julia's death was never solved. When Sherlock Holmes enters the case in order to protect Helen, he inevitably solves the two-year-old "locked-room murder mystery" as well as saving Helen from the same fate as her sister's. 

Another event that causes Helen Stoner to fear for her life and to go to Sherlock Holmes for help is her being only recently moved into the room that was occupied by Julia at the time of her agonizing death. Helen doesn't like being there. She can't sleep well in the strange room which keeps reminding her of the night her sister died in her arms. It is because Helen suffers from insomnia in this room, and possibly because she has intuitive suspicions of her stepfather in the room next-door, that she is awake at around three o'clock in the morning when she hears the low whistle.

It is this third event, the whistle, that causes her greatest fear and prompts her to leave for London as soon as it is daylight in order to bring her problem to the great detective. As she tells him during their interview:

"Imagine, then, my thrill of terror when last night, as I lay awake, thinking over her terrible fate, I suddenly heard in the silence of the night the low whistle which had been the herald of her own death." 

Helen doesn't know it, but the "speckled band," the deadly snake, must have been in bed with her at the time she heard the whistle. It would have been slithering silently up the dummy bell-rope while she remained in bed wide awake and only waiting for daylight before she could leave for London.

Helen Stoner is so afraid because her twin sister Julia died under mysterious circumstances at their home two years previously, and now she fears her turn is next. Their home is a grim and gloomy place owing to the presence of their stepfather, Dr Roylott, who is a fearsome, violent man, and Julia died suddenly in her own bedroom one night. There is no real clue as to what happened, but Helen found her in extreme terror, and babbling something about 'a speckled band'. A few nights before she died, Julia had told her about hearing a strange whistle at night. Just recently, Helen has had to move into her sister's old room where she died, and she too has heard the strange whistle. Helen is terrified that this whistle heralds her death, and so she has come immediately to consult Holmes.

Helen arrives 'in a pitiable state of agitation', as Watson sympathetically notes. She is wearing a black veil which increases the whole air of foreboding that hangs around her. Holmes adopts a soothing manner and helps to calm her fears. Of course, Holmes also goes on to solve the mystery of her sister's death, in which Dr Roylott is revealed as the culprit. Roylott has a deadly pet, a snake which he trained to climb into Julia's room at night, and which he used to summon back by a whistle - the whistle that Julia and Helen had heard. The 'speckled band' referred to the apprearance of the snake. Helen, however, has saved herself by coming to ask Holmes's help, and the snake ends up killing Dr Roylott, so that he is justly punished.

Helen Stoner came to Sherlock Holmes out of pure fear.  Her physical appearance even conveyed fear.  She had

“….restless frightened eyes, like those of some hunted animal.” (pg 2)

She tells Sherlock and Dr. Watson that she lives with her stepfather, who is the sole survivor of a family named Roylott.  At one time they owned

“……into Berkshire in the north, and Hampshire in the west.” (3)

However, due to wasteful living and gambling, nothing was left.  They were now broke and limited to a few acres and an old house that has a “crushing” mortgage.  Her stepfather, aware that his inheritance was very small, borrowed some money as a young man, got a medical degree, and practiced in Calcutta, India. He married Helen’s mother in India.  However, in a fit of anger, he killed his Indian butler and spent a long time in prison.  Afterwards he returned to England.

Helen and her sister, Julie, were twins and from a previous marriage.  Their mother had money and gave all of it to Dr. Roylott when they were married.  A certain sum was to be given to the girls when they married. 

Shortly after returning to England, Her mother died in a railroad accident. At that time, Dr. Roylott took the girls and moved to that old family home.  The money from their mother seemed to cover all expenses.  But her stepfather changed a lot after that.  He shut himself up in the house and only came out to have horrible fights with anyone who had the misfortune of crossing his path.  He became the

“….terror of the village, and the folks would fly at his approach, for he is a man of immense strength, and absolutely uncontrollable in his anger.” (pg 4)

Julie, Helen’s twin, died two years before her visit to Holmes.   She is the reason Helen has come to Sherlock Holmes.  At the time of her death, Julie was engaged.  Helen goes on to describe the home and how all the bedrooms were situated.  The night of her death Julie came to Helen’s room and asked if she ever heard whistling during the night.  Helen had not, but Julie distinctly heard whistling around three in the morning.  Julie went back to her room and locked the door because the doctor kept a cheetah and a baboon.  They needed the added feeling of security. 

During the night there was a wild scream.  Helen knew it was her sister.  Her sister collapsed to the floor and convulsed as if in severe pain. 

“….she slowly sank and died without having recovered her consciousness.” (pg 6)

Now Helen is engaged to be married. She has had to move into her sister’s bedroom due to repairs being made on the old house.  She has started hearing whistles.  She could not sleep, and as soon as she could, she came to Sherlock Holmes.  She is scared that the same thing that happened to her sister will happen to her.

My copy of the story is off the internet.  The page numbers may not coincide with yours but they should be close.

I actually don't think that Helen Stoner was aware that she was in grave danger when she went to visit Holmes. She went simply due to the low whistle which she heard in the middle of the night she had to spend in her sister's room.

It is Holmes who suspects that there is a danger to her life and makes an appointment to visit her soon so that he may investigate the cause behind the whistle she heard. Holmes makes a plan to discover the reality that night and gives strict instructions to Ms. Stoner. She is to return to her old bedroom while Holmes and Watson enter the room in which she heard the whistle and wait.

Eventually, the whistle sounds and a snake enters the room through an air ventilator from the father's room next door with the use of a rope that had been placed on top of the bed. Holmes hits the snake which in fear returns into the ventilator and ends up biting the father. The snake is revealed to be the most poisonous snake from India.

Although Helen Stoner came with the feeling that there was something strange taking place in her home, it was really Holmes who understood the seriousness of the matter and the risk to her life thanks to his keen sense of reasoning and intuition.

In The Adventure of the Speckled Band by Sir Arthur Conan Doyle, several circumstances create parallels between Helen Stoner's situation and those of her deceased sister, arousing the suspicions of Holmes and the reader that there is some evil afoot. 

First, Helen's room is being repaired and thus Helen is compelled to move into the room where her sister died. As the repairs appear to be unnecessary and are being carried out under the orders of her unpleasant stepfather, Sir Grimesby Roylott, this makes her uncomfortable.

Next, Helen is now engaged to be married, just as Julia was immediately before she died. In both cases, the stepfather had control over the family fortune in a manner that would end with the marriage of the sisters. 

Finally, Helen has been hearing strange noises in the night. 

When Helen Stoner visits Sherlock Holmes seeking his help in discovering how her twin sister, Julia died suddenly two years earlier, she is having experiences similar to Julia's before she died.

Helen has recently gotten engaged to be married, Julia was going to be married when she suddenly died from mysterioius causes.

Helen has been sleeping in Julia's old bedroom, at the request of her step-father; the house is undergoing renovation.

Helen has, of late, since she is sleeping in Julia's old room been hearing whistling sounds in the night.

"Because during the last few nights I have always, about three in the morning, heard a low, clear whistle. I am a light sleeper, and it has awakened me." (Conan Doyle)

Helen Stoner goes to see Sherlock Holmes for help because she is scared for her life.  Two years earlier her sister Julia died suddenly without warning or sickness.  Now, just recently, her stepfather, Dr. Roylott has asked Helen to sleep in her dead sister's old room due to renovations being done on the house.

Since Helen has been sleeping in Julia's old room, she has been hearing strange noises and has grown terrified for her life.  Her stepfather has become cold and distant towards her, since her announcement of her engagement.

Helen Stoner seeks protection from Sherlock Holmes and answers as to why her sister Julia died and what is it that so frightens her in Julia's old room.

From a purely practical perspective, the author had to have Helen come to see Sherlock Holmes at his Baker Street flat because that was the only way he could become involved in the case. Many of his cases begin with someone coming to him for advice or assistance. Jabez Wilson of "The Adventure of the Red-headed League" is another example. It is really hard to believe that a man would come to Holmes because of that business with the Red-headed League, but Holmes had to get involved in the situation somehow. These are the kinds of plot problems Doyle always had to cope with, especially when they involved very little in the way of remuneration. Ostensibly, Helen comes to Holmes because she is terribly frightened and still mystified by the strange death of her sister. The initial interview is short and unproductive. She lives at a great distance away. Holmes' involvement with her problem seems hard for the reader to accept.

Helen has always been wary of the way her twin sister Julia died.  Julia died right before her wedding and now with her own nuptials not to far away Helen begins to notice some of the same things that Julia had told her about....the whistle and clang in the dead of night.  She has also been made to sleep in Julia's old room.  Holmes had helped a friend of Helen's and she didn't know where else to turn.