In the novel, both Clithero and Huntly are sleepwalkers, although at the beginning of the book Huntly does not realize it. Sleepwalking is prevalent in the story, and Brown uses this device to drive the plot of the novel. For example, Huntly first notices Clithero while Clithero is sleepwalking near the Elm tree. This is what leads Huntly to investigate into Clithero's activities further, and why Huntly accuses Clithero of killing Waldegrave. It is while Huntly is following a sleep-walking Clithero that he first comes to the cave, which plays a major role in the plot. The entire second half of the novel revolves around the travelings of Huntly as he tries to return home; this occurs because Huntly wakes up in the bottom of a cave which he entered into by sleep-walking. Waldegrave's papers also mysteriously disappear, but later the reader learns that they were misplaced by Huntly during the night. Because Huntly was sleepwalking while he did this, he has no recollection of the events and the missing papers are therefore a great concern to him. At the end of the novel, Huntly no longer has troubles with sleepwalking.
Morality and Truth
According to Scott Bradfield, "Brown's notion of truth is so deeply private, so radically democratic, it never firmly or fully establishes itself anywhere or in any one person. All people stand equal in their judgment of the truth, because no permanent, instantly accessible field of knowledge exists to which they can submit." This idea can be found in this novel, especially in Clithero and Huntly. In Clithero's tale, for example, he goes to kill his caretaker Mrs. Lorimer, because he killed her brother. In Clithero's mind, he reasons that Mrs. Lorimer would be better off dead then learning about the death of her brother, especially because she herself said that she could not live with the knowledge of his death. Clithero therefore thinks that what he is doing is an act of mercy instead of murder. When Huntly first hears this tale, he is moved by compassion and also twists his reasoning and logic to come to that conclusion. However, at the end of the novel, when Clithero goes out in search for Mrs. Lorimer again, Huntly realizes his mistake.
Huntly also has many moral dilemmas in this novel. In the last half of the novel when he is called upon to kill Indians, he says that "My aversion to bloodshed was not to be subdued but by the direst necessity." Those dire circumstances occur, and soon Huntly has killed three Indians, to which he remarks, "Three beings, full of energy and heroism, endowed with minds strenuous and lofty, poured out their lives before me. I was the instrument of their destruction. This scene of carnage and blood was laid by me. To this havock and horror was I led by such rapid footsteps!" Huntly mourns the fact that he had to take human life, however, later in the book he learns that one of the Indians he had slain might have been responsible for killing Waldegrave, and this knowledge comforts his conscience. Huntly's justification of killing is similar to Rodion Romanovich Raskolnikov's justification in Crime and Punishment. They both see their actions as fulfilling a higher and more noble purpose. In this novel there seems to be no value for human life, especially Indian life.
In his preface, Brown claims that he will not use the same means as previous authors to create the Gothic feel. That is, he will not use "puerile superstition and exploded manners; Gothic castles and chimeras." However, as one continues to read through the book they soon find that Brown didn't completely live up to his promise. Brown creates the Gothic feel of the novel in order to create suspense. He does this through scenery and setting, mysterious characters, hidden secrets, and so forth. For example, the cave, which is a key element of the novel, is described as being completely dark. Not only that, but there are various paths within the cave that one can take, making the cave mysterious as well. Another example is the character Arthur Wiatte. His motives are to destroy and tear down. One might say he shows signs of having the Imp of the Perverse, which is when one does evil simply because it is evil.
Coincidence also occurs frequently. In one instance, Huntly is trying to open an enigmatic wooden box. While this would be impossible to most people, Huntly is able to open it because he just so happens to be a wooden box maker. Another time, the path in the cave that Huntly takes leads right up to where Clithero is hiding. Many of the characters that were in Clithero's tale also happened to be known by Huntly, for example, Sarsefield. Huntly barely escapes death multiple times. Once, a log bridging a large chasm allows Huntly to escape a panther, and falls just as the panther is crossing over, saving Huntly's life. Another time Huntly manages to somehow escape being shot at repeatedly by jumping into a nearby river. These instances add to the suspense of the novel, as well as its Gothic tone.