Stoke Moran is a house where wild animals roam free, while young women are imprisoned. Helen and Julia Stoner both lock themselves in their rooms at night for fear of the baboon and the cheetah, but their captivity is more psychological than physical. No one attempts to prevent Helen from going to London to consult Sherlock Holmes, but Roylott follows her and demands that Holmes divulge what she has said, though he must know that such consultations are confidential.

Helen makes it clear to Holmes that neither she nor her sister had much opportunity to meet other people of their own age, particularly men. Dr. Roylott is clearly anxious that the girls should not be able to escape from his clutches through marriage. Both sisters seize one of the few opportunities they have. Julia becomes engaged to a major in the Marines, whom she meets on a short visit to her aunt’s house. Helen agrees to marry an old friend who lives nearby. In neither case is love mentioned, and it appears that the main motive for marriage is to obtain their freedom from Roylott.

To some extent, the science of deduction is a theme of all the Sherlock Holmes stories. Holmes, after all, is a private detective, who has neither the resources nor the legal authority of the police force. Clients come to him because his mental abilities and his logical approach are unique. Holmes often begins a consultation by displaying his deductive powers, as he does with Miss Stoner in “The Adventure of the Speckled Band,” observing that she has traveled to London by train that morning and that she drove to the station in a dog-cart. However, in this instance he also concludes their conversation with a more substantial display of observation and deduction, when he says that she has been protecting Dr. Roylott by failing to mention his violence against her.

Holmes himself sometimes observes that it is a mistake for him to explain his method, since people who are amazed at what appears to be supernatural knowledge lose this sense of wonder when they understand the observations on which Holmes’s deductions are based. However, the reader and Watson are both compelled to admire Holmes’s application of his methods, since the clues are strewn throughout the story. “The Adventure of the Speckled Band” contains a particularly large number of clues, including the whistle, the metallic clang, the ventilator, the bell-rope, the bed bolted to the floor, the safe, the saucer of milk, and the dog-lash. The way in which Holmes arranges these clues to form a coherent sequence of events is a masterpiece of scientific deduction.

Watson mentions in the first paragraph of the story that Holmes chooses his cases “rather for the love of his art than for the acquirement of wealth.” When Miss Stoner raises the question of payment for his services, he waves it away with a similar observation: “my profession is its reward.” This contrasts sharply with the attitude of Dr. Roylott, who is prepared to murder two young women to ensure that his income remains at £750 a year, rather than diminishing to £250.

It is significant that this investigation into the doctor’s income is the first one Holmes makes, immediately after breakfast on the morning when he begins to look into the case. Helen Stoner also stresses the topic of money when she first mentions Roylott, saying that his family was once “among the richest in England,” but the doctor himself inherited no money and had to depend on his medical practice for a living. His marriage to Mrs. Stoner made him relatively wealthy, and he was prepared to go to extraordinary lengths to hang on to this income, despite the fact that the austerity of his lifestyle and the dilapidated condition of his house suggest that he did not spend much of it.

Dr. Roylott is a highly intelligent man and was a skilled doctor, who quickly built up a large practice in India. He could have used his talents to become a productive member of society and an influence for good in the world, as Dr. Watson has done. However, Dr. Roylott becomes a criminal when his intelligence is perverted through avarice and an apparently pathological violence of temper. Watson describes his face as being “marked with every evil passion,” and it is clear throughout the story that his cleverness, his professional abilities, his knowledge, and his physical strength have been turned exclusively toward vicious objectives for many years. Holmes himself makes this point when he realizes how the crime was committed:

When a doctor goes wrong he is the first of criminals. He has nerve and he has knowledge. Palmer and Pritchard were among the heads of their profession.

In this allusion to the criminal careers of Dr. William Palmer and Dr. Edward Pritchard, both well-known poisoners who were executed in the middle of the nineteenth century, Conan Doyle associates his fictional villain with real physicians who used their knowledge to kill rather than to cure.