In W.W. Jacobs' "The Monkey's Paw," the overriding conflict is the result of his ability to trick the reader into a false sense of comfort is presenting a tale that seems to have little "serious intention." This begins with the casual development of the story's mood.
The story begins with the weather, perfect for a scary story:
Without, the night was cold and wet..."Hark at the wind," said Mr. White.
Keeping the weather outside at bay, while it remains cozy and warm inside, mimics (foreshadows) the conclusion of the story: keeping what the parents believe to be their undead son resurrected by the monkey's paw from entering the house. These kind of details aid in the plot development—pointing us finally to the horror of the "overriding conflict"...do the Whites accept their dead son or leave him at rest?
"Magic" is present in the casual introduction of not only the paw, but seemingly benign presence of Sergeant-Major Morris.
"Monkey's paw?" said Mrs. White curiously.
"Well, it's just a bit of what you might call magic, perhaps," said the sergeant-major off-handedly.
From the introduction, the reader is given no sense that this is a horror story. The author's use of understatement is incredibly effective: the presentation of the seemingly inconsequential paw precedes three wishes, which in themselves are not frightful things: they are the stuff fairy tales are made of. However, surprisingly these innocent wishes will only heighten the fear and danger that has been placed within the family's midst. Morris' casual introduction (except for the description of his whitened "blotchy face") as he gives information "off-handedly," also offers a sense of the unknown in terms of the place the paw comes from (mysterious, unfamiliar regions where a "fakir"—a man capable performing marvels or wonders was involved) and the power of the supernatural. Morris uses the phrase...
...it's just a bit of what you might call magic, perhaps...
A sense of the unknown continues with Mrs. White's reflection:
Sounds like the Arabian Nights...
The word "magic" is tame by comparison to the disaster that visits the White family—once again this shows Jacobs' adept use of understatement. In delving into the unknown—magic that (we can infer by his expression) has caused Morris a overwhelming amount of suffering—the stage is now set for tragedy, as inferred by Morris' implied experiences of woe and his warnings (also foreshadowing). Perhaps the line that best explains the central conflict of the story can be found in the fakir's reasoning for cursing the paw to begin with—though "curse" is never used...only the harmless "spell"—
[The fakir] wanted to show that fate ruled people's lives, and that those who interfered with it did so to their sorrow.
Based on the fakir's intent, the conflict confronting the Whites is a result of attempting to change their fate with their first wish. The other wishes are spent in trying to fix what happens to them because of the first wish. And in the end, as with Morris, they are changed forever.
In light of these details, a thesis statement I might use is:
With the introduction of magic, wishes and fate, Jacobs casually introduces the reader to a tale that gives the appearance of simplicity and light entertainment; however, his masterful manipulation of events actually creates heart-rending conflicts with fearful consequences for which the reader is totally unprepared.