There were several strange modifications to the rooms in which both of the Roylott ladies resided. The fact that there was any work going on at all at the house was immediately suspicious:
Some scaffolding had been erected against the end wall, and the stone-work had been broken into, but there were no signs of any workmen at the moment of our visit.
As the Roylott estate was no longer wealthy, and the rest of the building was in disrepair, it was odd that any work should be done at all. And, if there were necessary repairs, there were no workmen to complete them.
Holmes then identified the unusual adaptations to the house. His first concern was the ventilation system:
There are one or two very singular points about this room. For example, what a fool a builder must be to open a ventilator into another room, when, with the same trouble, he might have communicated with the outside air!
Secondly, Holmes observed that the recently installed bell-pull served no discernable purpose and did not work. His third concern was the positioning and modifications to Miss Roylott’s bed-
"It was clamped to the floor. Did you ever see a bed fastened like that before?"
Holmes surmises that the adaptations have been made to facilitate Grimesby Roylott's evil plan and, of course, he is right.
Several things evoked Holmes' suspicion that there was indeed foul play going on:
-the unnecessary "renovation" of the wing where Julia's room was located.
-the strange whistling sound Julia had heard at night coming through the bedroom's walls
-the bell pull coming down from the ventilator grid, which looked recently installed but didn't work
It takes Holmes' deductive reasoning and logic to put two and two together to figure out what is going on before a second disaster takes place. This time, however, there are enough clues along the way for the reader to "play sleuth" along with Holmes, heightening the suspense and interest of the story.
Helen Stoner seeks Holmes' help because she fears for her life as she is convinced that she will die just like how her sister died. Helen and her sister Julia live with their stepfather Dr.Roylott. Two years ago Julia got engaged and just a fortnight before her wedding she died a terrible death under mysterious circumstances screaming, 'Oh, my God! Helen! It was the band! The speckled band!' She had informed Helen earlier that she often heard a 'low clear whistle' at three in the morning.
Now, Helen is in a similar situation. She has been engaged to one Percy Armitage and is to be married in the coming Spring season. But two days ago some repairs were started in her room and she has been compelled to stay in the very same room in which her sister died. Last night when she was sleeping on the same bed in which her sister met her tragic end,to her horror, she heard the same low whistle which signalled her sister's tragic death. So, in sheer fright she has taken the first train to London and rushed to meet Sherlock Holmes to seek his advice as to how to save her life from impending death.
Sherlock Holmes and Dr. Watson visit Miss Helen Stoner at her step father's country manor at Stoke Moran. Holmes makes a careful and detailed study of the room in which Helen's sister Julia died, and where she has been asked to sleep now because some repairs are being carried out in her own room. Holmes' suspicions have been aroused because on examining the room from the outside he discovered that no repairs were necessary to Helen's room and that the repairs were only a pretext to make Helen sleep in the same room in which her sister Julia died:
"Pending the alterations, as I [Sherlock Holmes] understand. By the way, there does not seem to be any very pressing need for repairs at that end wall."
"There were none. I [Miss Helen] believe that it was an excuse to move me from my room."
"Ah! that is suggestive."
Holmes then examines Helen's room from inside and discovers that there is dummy bell cord hanging just above her bed and a ventilator which opens into the adjacent room which is Dr. Roylott's:
"Very strange!" muttered Holmes, pulling at the rope. "There are one or two very singular points about this room. For example, what a fool a builder must be to open a ventilator into another room, when, with the same trouble, he might have communicated with the outside air!"
"That is also quite modern," said the lady.
"Done about the same time as the bell-rope?" remarked Holmes.
"Yes, there were several little changes carried out about that time."
"They seem to have been of a most interesting character -- dummy bell-ropes, and ventilators which do not ventilate.
At the end of the story Holmes explains to us that the dummy bell rope and the ventilator were necessary for the poisonous snake to slither down and bite its victim who would be sleeping on the bed down below:
My attention was speedily drawn, as I have already remarked to you, to thisventilator, and to the bell-rope which hung down to the bed. The discovery that this was a dummy, and that the bed was clamped to the floor, instantly gave rise to the suspicion that the rope was there as a bridge for something passing through the hole and coming to the bed. The idea of a snake instantly occurred to me, and when I coupled it with my knowledge that the doctor was furnished with a supply of creatures from India, I felt that I was probably on the right track.