In Chapter 3, in an instance of foreshadowing, Holmes responds to the supernatural theory behind the Baskerville murders and the devilish Hound and states:
The devil’s agents may be of flesh and blood, may they not?
At this point, most characters believe that the hound has come from Hell in pursuit of a Baskerville who sold his soul to the Devil. But Holmes rejects the legend of the Hound of the Baskervilles as a superstitious fairy tale, suggesting here that the supposed reappearance of the hound on the night of Sir Charles's death may not have supernatural origins at all.
By suggesting that the "devil's agents" are in fact "flesh and blood," Holmes foreshadows the novel's ending, which reveals that the supposed “hellhound” is not some supernatural creature but a mix between a bloodhound and mastiff. In Chapter 14, it is revealed that Jack Stapleton paints the hound in phosphorus in order to give it its terrifying, otherworldly glow. In other words, the "devil's agent" turns out to be Stapleton, a flesh-and-blood human being, after all. Through this use of foreshadowing, then, the story hints that the apparently supernatural has a natural, even scientific, explanation that can be deduced through the use of logic and reasoning.
Stapleton, who has spent two years learning the safe ways to travel through the Grimpen Mire, ends up being sucked into the mire when he flees from Holmes, Watson, and Lestrade after attempting to murder Sir Henry Baskerville.
Stapleton's fate is foreshadowed in Chapter 7, when Stapleton warns Watson about the dangers of Grimpen Mire:
'That is the great Grimpen Mire,’ said he. ‘A false step yonder means death to man or beast. Only yesterday I saw one of the moor ponies wander into it. He never came out. I saw his head for quite a long time craning out of the boghole, but it sucked him down at last. Even in dry seasons it is a danger to cross it, but after these autumn rains it is an awful place. And yet I can find my way to the very heart of it and return alive.
Moments later, the two observe a pony sinking in the moor:
Something brown was rolling and tossing among the green sedges. Then a long, agonized, writhing neck shot upwards and a dreadful cry echoed over the moor. It turned me cold with horror, but my companion’s nerves seemed to be stronger than mine.
Although Stapleton is unnerved, Watson is disturbed. The Grimpen Mire is treacherous territory, dangerous to anyone or anything that makes a false move. In Chapter 14, Jack Stapleton flees to evade capture for his crimes. Beryl Stapleton tells Watson and Holmes that Jack must have fled to an island in the middle of the Grimpen Mire, where Jack hid the hound. But when Watson and Holmes investigate the Mire the next morning, all Watson and Holmes find left of Stapleton is his boot:
Once only we saw a trace that someone had passed that perilous way before us. From amid a tuft of cotton-grass which bore it up out of the slime some dark thing was projecting. Holmes sank to his waist as he stepped from the path to seize it, and had we not been there to drag him out he could never have set his foot upon firm land again. He held an old black boot in the air. ‘Meyers, Toronto’, was printed on the leather inside. Somewhere in the heart of the great Grimpen Mire, down in the foul slime of the huge morass which had sucked him in, this cold and cruel-hearted man is for ever buried.
The final image of Jack's boot recalls the image of the wild pony, captured by the Mire and lost forever. In a twist of fate, the location that helped Stapleton evade capture for his cunning crimes ends up capturing him, once and for all.
In Chapter 7, in an instance of foreshadowing, Beryl Stapleton tries to warn Watson, who has been with Jack Stapleton, that he is in grave danger. Though Watson doesn't know it, the seemingly harmless Stapleton is a cold-blooded, ruthless killer:
‘I cannot explain.’ She spoke in a low, eager voice, with a curious lisp in her utterance. ‘But for God’s sake do what I ask you. Go back, and never set foot upon the moor again. [...] ‘Man, man!’ she cried. ‘Can you not tell when a warning is for your own good? Go back to London! Start tonight! Get away from this place at all costs! Hush, my brother is coming! Not a word of what I have said.'
Unbeknownst to them, Beryl has been posing as Stapleton’s sister when she is actually his wife. Jack physically abuses Beryl so she is fearful and mostly obedient to him. Despite this, when she has a moment alone with Watson, she seizes the opportunity to advise him. This moment importantly offers a clue to the reader and foreshadows the moment Stapleton’s true nature is revealed. In reality, he is a cunning mastermind who is heir to the Baskerville inheritance and behind the mysterious crimes. Stapleton uses his resources as an entomologist and botanist to lay the groundwork for his nefarious plans. He finds a safe path through the Moor, where he hides the hound, and obtains phosphorus, which gives the hound the supernatural glow that frightened Sir Charles Baskerville to death. But, at this point, the reader doesn't know any of that, so Beryl's warning builds suspense and foreshadows the revelation to come.
In Chapter 11, Watson finds the mysterious Man on the Tor's hideout. Unnerved by his presence and this strange twist in events, Watson uses a metaphor to suggest the person behind these occurrences is a shrewd and cunning mastermind, one step ahead of him:
Always there was this feeling of an unseen force, a fine net drawn round us with infinite skill and delicacy, holding us so lightly that it was only at some supreme moment that one realized that one was indeed entangled in its meshes.
As Watson investigates the Moor, he begins to feel an increasing sense of danger. Threats loom everywhere—in the strange, mournful calls he hears at night and the unknown whereabouts of the criminal Selden. At this point in the story, it is clear that danger is near, and the image of Watson and Holmes captured in a net heightens the dramatic tension of the moment.
The story’s use of metaphor in this moment is also an instance of foreshadowing. The description of a net closing in on Watson and Sir Henry alludes to the naturalist Jack Stapleton and his butterfly net, a recurring motif. Before Watson approaches the hut, he describes himself walking “as warily as Stapleton would do when with poised net he drew near the butterfly.” Holmes brings up butterflies in reference to Stapleton again in Chapter 13 when it is revealed that he is a long-lost Baskerville heir and therefore has a motive for the crimes. The chapter is fittingly titled “Fixing the Nets”:
We have him, Watson, we have him, and I dare swear that before tomorrow he will be fluttering in our net as helpless as one of his own butterflies. A pin, a cork, and a card, and we add him to the Baker Street collection!
Building the butterfly motif, Holmes uses a simile and compares Stapleton to one of the naturalist's subjects of inquiry. Watson first meets Stapleton out on the Moor, “dressed in a grey suit and wearing a straw hat" and carrying a specimen box and a green butterfly-net, a getup that turns out to be a clever coverup to explain his frequent presence on the Moor.
In Chapter 11, Watson finds the mysterious Man on the Tor's hideout. Unnerved by his presence and this strange twist in events, Watson uses a metaphor to suggest the person behind these occurrences is a shrewd and cunning mastermind, one step ahead of him:
Always there was this feeling of an unseen force, a fine net drawn round us with infinite skill and delicacy, holding us so lightly that it was only at some supreme moment that one realized that one was indeed entangled in its meshes.
As Watson investigates the Moor, he begins to feel an increasing sense of danger. Threats loom everywhere—in the strange, mournful calls he hears at night and the unknown whereabouts of the criminal Selden. At this point in the story, it is clear that danger is near, and the image of Watson and Holmes captured in a net heightens the dramatic tension of the moment.
The story’s use of metaphor in this moment is also an instance of foreshadowing. The description of a net closing in on Watson and Sir Henry alludes to the naturalist Jack Stapleton and his butterfly net, a recurring motif. Before Watson approaches the hut, he describes himself walking “as warily as Stapleton would do when with poised net he drew near the butterfly.” Holmes brings up butterflies in reference to Stapleton again in Chapter 13 when it is revealed that he is a long-lost Baskerville heir and therefore has a motive for the crimes. The chapter is fittingly titled “Fixing the Nets”:
We have him, Watson, we have him, and I dare swear that before tomorrow he will be fluttering in our net as helpless as one of his own butterflies. A pin, a cork, and a card, and we add him to the Baker Street collection!
Building the butterfly motif, Holmes uses a simile and compares Stapleton to one of the naturalist's subjects of inquiry. Watson first meets Stapleton out on the Moor, “dressed in a grey suit and wearing a straw hat" and carrying a specimen box and a green butterfly-net, a getup that turns out to be a clever coverup to explain his frequent presence on the Moor.
Stapleton, who has spent two years learning the safe ways to travel through the Grimpen Mire, ends up being sucked into the mire when he flees from Holmes, Watson, and Lestrade after attempting to murder Sir Henry Baskerville.
Stapleton's fate is foreshadowed in Chapter 7, when Stapleton warns Watson about the dangers of Grimpen Mire:
'That is the great Grimpen Mire,’ said he. ‘A false step yonder means death to man or beast. Only yesterday I saw one of the moor ponies wander into it. He never came out. I saw his head for quite a long time craning out of the boghole, but it sucked him down at last. Even in dry seasons it is a danger to cross it, but after these autumn rains it is an awful place. And yet I can find my way to the very heart of it and return alive.
Moments later, the two observe a pony sinking in the moor:
Something brown was rolling and tossing among the green sedges. Then a long, agonized, writhing neck shot upwards and a dreadful cry echoed over the moor. It turned me cold with horror, but my companion’s nerves seemed to be stronger than mine.
Although Stapleton is unnerved, Watson is disturbed. The Grimpen Mire is treacherous territory, dangerous to anyone or anything that makes a false move. In Chapter 14, Jack Stapleton flees to evade capture for his crimes. Beryl Stapleton tells Watson and Holmes that Jack must have fled to an island in the middle of the Grimpen Mire, where Jack hid the hound. But when Watson and Holmes investigate the Mire the next morning, all Watson and Holmes find left of Stapleton is his boot:
Once only we saw a trace that someone had passed that perilous way before us. From amid a tuft of cotton-grass which bore it up out of the slime some dark thing was projecting. Holmes sank to his waist as he stepped from the path to seize it, and had we not been there to drag him out he could never have set his foot upon firm land again. He held an old black boot in the air. ‘Meyers, Toronto’, was printed on the leather inside. Somewhere in the heart of the great Grimpen Mire, down in the foul slime of the huge morass which had sucked him in, this cold and cruel-hearted man is for ever buried.
The final image of Jack's boot recalls the image of the wild pony, captured by the Mire and lost forever. In a twist of fate, the location that helped Stapleton evade capture for his cunning crimes ends up capturing him, once and for all.