The tone of Dr. Jekyll and Mr. Hyde is foreboding and tense. This is achieved in part through the narrator’s constant withholding of information from the reader and the frequent use of violence as a tool of characterization in the text.
The relationship between Hyde and Jekyll is the puzzle that the novella is constructed around. Stevenson’s plot offers one inexplicable event after another, while at the same time denying Utterson any pat explanation for his friend’s increasingly erratic behavior. Utterson, being a reasonable man, proffers one plausible excuse after another (disease, madness, blackmail, and so on) for these events, but is unable to find any evidence for them. He is denied closure or cause for his friend’s actions time and time again.
The social code of silence around indiscretions means neither Enfield, nor Lanyon, nor anyone else will reveal what little they know to Utterson. Utterson is therefore powerless to grasp the thread connecting the events around him. As one violent event unfolds after another, the stakes of his floundering attempts at helping Jekyll grow higher and higher.
Frequent major and minor acts of violence add further tension to the narrative, and something tangible to the sometimes abstract evil explored in the book. On his way to Lanyon’s apartment, Hyde assaults a woman in the street:
Once a woman spoke to him, offering, I think, a box of lights. He smote her in the face, and she fled.
Hyde’s acts of violence are opportunistic, indiscriminate, and brutal. The attack on this woman, who has done nothing but speak to him, is borne out of Hyde’s stress after Jekyll’s unplanned transformation in a park. This episode illustrates Hyde’s lack of control over his emotions and urges. While a sinister, evil quality permeates Hyde’s manner and appearance, sadistic acts of violence are the primary tool of characterization the narration employs to depict Hyde’s antisocial tendencies. An assault marks almost every scene he is present in (the trampling of the girl, the Carew murder, the attack above). The narration stops to touch on the public’s reactions to Hyde in many of these scenes, which gives the story a kind of momentum as the public dislike of him shifts to a manhunt following Carew’s murder.