Arthur Conan Doyle sets up the plot in such a way that the major conflict in "The Adventure of the Speckled Band" becomes a conflict between Sherlock Holmes and Dr. Grimesby Roylott. This is mainly because Dr. Roylott makes a stormy appearance at 221B Baker Street very shortly after his stepdaughter Helen Stoner has told Holmes and Watson her long back-story and left. Dr. Roylott had traced her movements all the way from Stoke Moran to Baker Street. This was not hard to do because Helen had disguised herself by wearing a mourning dress and a heavy black mourning veil. Instead of disguising herself, however, she had made herself all the more conspicuous. There would have been very few young women, if any, traveling to London by train at that early honor, and only one wearing mourning clothes. Dr. Roylott could have easily found the cabbie who took Helen from Waterloo Station in London to Baker Street, and he could have found out by inquiring in the neighborhood that it was none other than Sherlock Holmes who lived at 221B.
When Roylott barges into the room he says:
"My stepdaughter has been here. I have traced her. What has she been saying to you?”
Holmes naturally refuses to give him any information about a client. Roylott makes a scene.
“I will go when I have said my say. Don't you dare to meddle with my affairs. I know that Miss Stoner has been here. I traced her! I am a dangerous man to fall foul of! See here.” He stepped swiftly forward, seized the poker, and bent it into a curve with his huge brown hands.
This is the only time the reader will see Dr. Roylott alive, but the little scene introduces him as a character and establishes that the conflict will be between Holmes and Roylott. The entire story could have been told without introducing Dr. Roylott until the very end, when he is found dead with his own snake wrapped around his head. But then the conflict, if any, would have been vague and hard to define. With this confrontation between the two men, the story becomes a conflict between them. The threat of violence by the half-mad Dr. Roylott hangs like a storm cloud over the entire story. Roylott tells Holmes to mind his own business; Holmes defies him and makes it his business to investigate the strange happenings at Stoke Moran. In the end it is Holmes who wins. The conflict is resolved when he drives the poisonous snake back through the ventilator and it bites its owner, causing him to die in agony in a few minutes.
Later Holmes will acknowledge that he was responsible for Roylott's death. This is how the conflict between the two men is resolved. One of them kills the other. If Roylott had come back unexpectedly and had found Sherlock Holmes on his property, the violent doctor was quite capable of trying to kill the intruder with one of the hunting guns he must have had on the premises. Holmes tells Watson:
"Some of the blows of my cane came home and roused its snakish temper, so that it flew upon the first person it saw. In this way I am no doubt indirectly responsible for Dr. Grimesby Roylott's death, and I cannot say that it is likely to weigh very heavily upon my conscience.”