Towards the end of Chapter 6, Stoker uses a combination of foreshadowing, imagery, and simile to generate a sense of dread and foreboding:
Today is a grey day, and the sun as I write is hidden in thick clouds, high over Kettleness. Everything is grey - except the green grass, which seems like an emerald amongst it . . . . Dark figures are on the beach here and there, sometimes half shrouded in mist, and seem "men like trees walking."
Mina's description of the physical landscape of Kettleness - its menacing ambience - creates a mysterious and unsettling image. Like the "dark figures" obscured by mist, the dark events of the future are obscured from both Mina and the reader, though the ominous mood created by this natural imagery foreshadows some series of menacing supernatural events.
Furthermore, the simile/image of "men like trees walking" reinforces the fact that supernatural forces are at work, conjuring up the image of enchanted trees walking up and down the beach. The statement "men like trees walking" is also an allusion to a Biblical passage in the Gospel of Mark, wherein Jesus heals a blind man. This biblical allusion contributes to the foreshadowing in this passage, implying that something that's unclear will soon be revealed.
Towards the end of Chapter 14, Seward remains confused about Van Helsing's thought process, not understanding why Lucy passed away nor how her death is linked with a series of other events. Stoker uses a striking combination of imagery and simile to describe Seward's intellectual position:
At present I am going in my mind from point to point as a mad man, and not a sane one, follows an idea. I feel like a novice blundering through a bog in a mist, jumping from one tussock to another in the mere blind effort to move on without knowing where I am going.
Dr. Seward, an intellectual though he is, finds himself in the same position as the reader - he is similarly in the dark, unable to discern connections between events. Van Helsing prompts him to open his mind to the supernatural (the "unscientific" or "impossible"), an effort which will clear this fog of mystery from his mind and allow him to view the truth. This intellectual fog that Seward (and other characters) are immersed in parallels the literal fog that often rolls in as a premonition of evil—the result of Dracula's dark influence over nature.
At the beginning of Chapter 16, Stoker uses striking natural imagery to set the mood for the gruesome work that Dr. Seward, Van Helsing, Quincey, and Arthur must carry out in their efforts to lay Lucy to rest:
Never did tombs look so ghastly white; never did cypress, or yew, or juniper so seem the embodiment of funeral gloom; never did tree or grass wave or rustle so ominously; never did bough creak so mysteriously; and never did the far-away howling of dogs send such a woeful presage through the night.
In this passage, as in the passages where Jonathan Harker describes the landscape of Transylvania, natural forces collude with the men's pre-existing fears to make every movement, every noise an omen of terrible things to come. Noises and images that would by day be welcoming—or at the very least a neutral presence—become menacing. Each natural element, from the trees to the grass to the dogs, takes on a supernatural identity and purpose derived from the nighttime. In gothic literature, the reader learns to take cues from the behavior of the natural world; in this scene, every natural image becomes a "woeful presage," foreshadowing the terrible evils that the protagonists will soon encounter.
As Arthur, Van Helsing, Quincey, and Dr. Seward enter Lucy's tomb in Chapter 16 to dispose of the vampire, they encounter a woman much changed from the person they knew, both in visage and demeanor. Stoker uses visceral imagery to showcase this change:
My own heart grew cold as ice, and I could hear the gasp of Arthur, as we recognized the features of Lucy Westenra, but yet how changed. The sweetness was turned to adamantine, heartless cruelty, and the purity to voluptuous wantonness.
Lucy's appearance as a vampire is contrasted with her former visage—one, for the men who view her, is the Un-Dead image of sexual impurity; the other, lately deceased, was a woman of the utmost chastity and Christian "purity." These dual images reflect the sexual mores of Stoker's time, where women's morality was heavily tied to their "sexlessness"; or, rather, their ability to transcend baser animal instincts. As a sexual being, Lucy's vampire persona must appear much different from her human persona, in both word and deed. In order for Lucy to remain a moral character, in spite of the vampire's pollution, she must remain sexually pure in contrast to the vampire. This dichotomy is an important one, appearing throughout the text of Dracula.
