The novel's opening sentences, as Lockwood reflects on his first visit to Wuthering Heights and meeting Heathcliff, are packed with foreshadowing:
1801—I have just returned from a visit to my landlord—the solitary neighbour that I shall be troubled with. This is certainly a beautiful country! In all England, I do not believe that I could have fixed on a situation so completely removed from the stir of society. A perfect misanthropist’s Heaven—and Mr Heathcliff and I are such a suitable pair to divide the desolation between us. A capital fellow!
Some of the irony of this passage is due to the fact that, though Lockwood calls himself a "misanthropist," he's clearly exaggerating—he means something more like "introvert." If he truly hated the company of fellow humans, Lockwood wouldn't have sought out his landlord and neighbor, nor would he have cheerfully judged him "a capital fellow."
The greater irony, though, is the fact that, far from being "a capital fellow," Heathcliff is a misanthropist—though neither Lockwood nor readers know that yet. Despite initial appearances to the contrary, Heathcliff isn't a sociable neighbor with whom to "divide the desolation" of this remote country. In fact, Heathcliff has been a terror to his former neighbors at Thrushcross Grange, but Lockwood will only learn this as Nelly tells him the whole story over the course of the novel. The passage thus foreshadows that, indeed, the Grange and the Heights are incredibly remote from "civilized" society, and in this lonely setting, Heathcliff will be Lockwood's main source of entertainment—though not in the neighborly way he expects, but as the villain of a tale spanning decades.
When Lockwood visits Wuthering Heights for the first time, the novel uses melancholy, Gothic imagery to indicate that the neighboring house is a forlorn, isolated, tempestuous place. Lockwood's visit also foreshadows the whole history of the place that Nelly will tell Lockwood about over the course of the novel.
Wuthering Heights is the name of Mr Heathcliff’s dwelling, ‘Wuthering’ being a significant provincial adjective, descriptive of the atmospheric tumult to which its station is exposed in stormy weather. Pure, bracing ventilation they must have up there, at all times, indeed: one may guess the power of the north wind, blowing over the edge, by the excessive slant of a few, stunted firs at the end of the house; and by a range of gaunt thorns all stretching their limbs one way, as if craving alms of the sun.
The house's very name, "Wuthering Heights," is derived from the strong winds that buffet the place, hinting that it's not only subject to literal storms, but also figurative ones. By describing the thorn trees with their stretching limbs as "craving alms of the sun," the novel personifies the trees as beggars and the sun as a benefactor; this simile also suggests that the residents of Wuthering Heights rarely experience goodness (light) and long for it.
The house's exterior is also marked by Gothic imagery:
Before passing the threshold, I paused to admire a quantity of grotesque carving lavished over the front, and especially about the principal door, above which, among a wilderness of crumbling griffins, and shameless little boys, I detected the date ‘1500,’ and the name ‘Hareton Earnshaw.’
Gargoyles are characteristic of spooky old buildings in Gothic literature. Also, the name and date carved above the front door foreshadow the 300-year Earnshaw family history that Lockwood isn't yet acquainted with, which will propel much of the novel's drama. At this point, all he (and readers) know for sure is that Wuthering Heights is very old, mysterious, and forbidding.
When Lockwood spends the night at Wuthering Heights, he sees young Catherine Earnshaw's signature repeatedly scratched into the ledge beside his bed. Catherine's signatures foreshadow much of the novel's drama:
The ledge, where I placed my candle, had a few mildewed books piled up in one corner; and it was covered with writing scratched on the paint. This writing, however, was nothing but a name repeated in all kinds of characters, large and small—Catherine Earnshaw, here and there varied to Catherine Heathcliff, and then again to Catherine Linton.
The different surnames foreshadow Catherine's own conflicted identity and attractions. Catherine is born an Earnshaw, but her first and dearest friend is Heathcliff, and she also grows fond of neighbor Edgar Linton. She eventually marries Linton, but not before she goes through much inner turmoil (suggested by the carved names in her childhood room) and accidentally reveals to Heathcliff that she thinks their class differences make marriage impossible (though she actually loves him most).
Neither Lockwood nor the reader knows anything about Catherine's existence at this point in the story, so the scratched names mostly hint that there is some sort of romantic conflict yet to come. The mashup of Earnshaw, Heathcliff, and Linton also suggests that this conflict will make the novel's relationships somewhat confusing at times!
When Lockwood spends the night at Wuthering Heights, he dreams about Catherine's ghost trying to get in the window by his bed. At first, he thinks he hears a branch tapping on the window, but when he investigates, he finds himself clutching a ghostly hand. Morbid, terrifying imagery sets the tone for the tragic story to come:
[...] stretching an arm out to seize the importunate branch: instead of which, my fingers closed on the fingers of a little, ice-cold hand! The intense horror of nightmare came over me; I tried to draw back my arm, but, the hand clung to it, and a most melancholy voice sobbed, ‘Let me in—let me in!’ [...] ‘I’m come home, I’d lost my way on the moor!’
Up to this point, Lockwood has found his Wuthering Heights neighbors off-putting and strange, but with this dream, the novel takes a stark turn toward the downright frightening. The "icy" hand and weeping, "most melancholy" voice shock Lockwood, and readers, into realizing that Wuthering Heights has an even darker history than the house's Gothic architecture would suggest.
Soon after, when Lockwood asks, the voice identifies itself as Catherine Linton, not Earnshaw, even though Lockwood recalls having read "Earnshaw" etched into the bedside ledge many more times than "Linton." Lockwood doesn't yet know who Catherine is, much less that she married a Linton, which makes the ghost's existence seem more plausible, not a mere dream. Again, the dream foreshadows the whole history of Wuthering Heights that the household servant Nelly will eventually tell Lockwood.
The dream gets even more horrifying from here:
Terror made me cruel; and, finding it useless to attempt shaking the creature off, I pulled its wrist on to the broken pane, and rubbed it to and fro till the blood ran down and soaked the bed-clothes: still it wailed, ‘Let me in!’ and maintained its tenacious [grip], almost maddening me with fear.
Again, the shocking imagery of bloodied wrists and an unnaturally strong grip signals that the story of Catherine, Heathcliff, and Wuthering Heights will involve death in some way. The ghost's grief and persistence also suggest that Catherine Linton's story is still unresolved.
The night young Heathcliff runs off from Wuthering Heights, an unseasonable summer storm erupts, foreshadowing the heartache and animosity to come:
About midnight, while we still sat up, the storm came rattling over the Heights in full fury. There was a violent wind, as well as thunder, and either one or the other split a tree off at the corner of the building; a huge bough fell across the roof, and knocked down a portion of the east chimney-stack, sending a clatter of stones and soot into the kitchen fire.
The storm's "fury" and violence reflect the agitation at Wuthering Heights when Heathcliff doesn't reappear after disappearing into the night. In particular, this use of personification (as if the storm is sentient and angry) reflects Catherine's turmoil, since she now knows Heathcliff ran off because he overheard her say she couldn't marry him. Most of all, though, the storm's "fury" symbolizes Heathcliff's own anger, as he believes Catherine doesn't love him because of the way he's been "degraded" by Hindley's mistreatment of him at Wuthering Heights. It also foreshadows Heathcliff's vengeful fury against the Linton family hereafter (since Catherine marries Edgar Linton). The knocked-down section of the chimney anticipates the self-destructive havoc he'll wreak at Wuthering Heights when he returns one day.
Nelly reflects on Cathy's 16th birthday, when she and Cathy were out walking on the moors. She uses imagery conveying youth, promise, joy, and goodness:
She bounded before me, and returned to my side, and was off again like a young greyhound; and, at first, I found plenty of entertainment in listening to the larks singing far and near; and enjoying the sweet, warm sunshine; and watching her, my pet, and my delight, with her golden ringlets flying loose behind, and her bright cheek, as soft and pure in its bloom as a wild rose, and her eyes radiant with cloudless pleasure. She was a happy creature, and an angel, in those days. It’s a pity she could not be content.
Nelly describes Cathy as a "young greyhound," with boundless energy, and remarks affectionately on the young woman's carefree, innocent radiance—the "bright," "wild rose" complexion and "cloudless" happiness in her eyes. The natural environment reflects Cathy's joy, too, with singing larks and pleasant sunshine. Yet this lively, fruitful, promising imagery also foreshadows the loss of Cathy's innocence and freedom. Cathy is fresh and jubilant on the open moor, but she will soon be trapped, stagnant, and bitter as Heathcliff's prisoner at Wuthering Heights.
Given Nelly's perspective, looking back on this memory as she recounts it to Lockwood, the happy day on the moors has a wistful undertone ("She was a happy creature, and an angel [...] It's a pity she could not be content"). Nelly knows that Cathy met Heathcliff and Hareton on the moors that same day, which spelled the beginning of the end of her sheltered happiness. She implies that Cathy's encounter with the men of Wuthering Heights precipitated a loss of her "angelic" innocence, and that it stirred a latent discontentment in her. Her lively curiosity, then, ends up being her downfall, as she starts visiting the Heights and being pulled out of the protective world of the Grange that has fostered her innocence thus far.