constant, and certainly when Tom first meets with the Devil, Irving creates a mysterious, ominous and brooding tone suitable to the evil personage that Tom is going to meet with. Certainly, overall there is a delightfully humorous tone as Tom gets his just deserts, but that should not blind us to the message of this tale.

The mood--that attitude that an author evokes from his readers--in "The Devil and Tom Walker" is humorous and didactic.  Irving uses the story to satirize cold marital relationships and superstitious, greedy humans.  His satirical tone adds humor to the story, especially his description of Tom and his wife's attitudes toward one another. The author also intends for readers to learn a lesson from his story; so the mood is rather didactic.

Even though the story is one based on a dark legend of one selling his soul to the devil for personal gain, Irving tells it with wry humor.  When Irving describes both Tom Walker and his wife, he does so with a twinkle in his eye, saying, "...they were so miserly that they even conspired to cheat each other." Neither husband nor wife seem to have any fear of the devil because they are both too consumed with greed. Tom's wife sets off to find the devil and make her own pact because Tom doesn't want to give his wife the satisfaction and possible benefit from him selling his soul and so threatens not to go through with the deal.  When she doesn't return, Tom eventually goes in search of her - not because this is his wife who is missing and he misses her, but because when she left, she took some valuable household items with her and Tom wants them back.  Tom finds his wife's apron with only a heart and a liver in it.  So, the reader is told, "Tom consoled himself for the loss of his property, with the loss of his wife, for he was a man of fortitude. He even felt something like gratitude toward the black woodsman, who, he considered, had done him a kindness."  The humor is as unmistakeable as it is old.  The same sense of humor survives to the end of the story when, Tom, now rich from charging outrageous interest rates in his money-lending business, says in anger, "The devil take me if I have made a farthing!"  The devil then takes Tom.

The mood at the beginning of "The Devil and Tom Walker" starts out as dark and sinful. 

The setting that is determined to be a few miles from Boston, Massachusetts has a dark and evil feel to it. Some words used in the description that best support this idea are "dark grove," "night," "the Devil presided," and "ill-gotten." The place is described as a place that is very secluded where secret happenings take place. 

The events added to the setting indicate that the place was a good location for people to secretly bring money, hide it, stay on the lookout, and come back for it at another time. Everything in this situation describes mischief and evilness. 

Lastly, the initial descriptions of two of the characters in the short story are provided. Tom Walker and his wife are described as miserable people who hide everything they could from each other. 

Everything within the first few paragraphs of "The Devil and Tom Walker" point to a depressing, dreary mood. 

There are two aspects to the beginning of the story; a brief introduction of the treasure, and an introduction of Tom and his wife.

The treasure is introduced first, as a sort of prologue (one might imagine that a modern retelling, particularly a film, would show these events as a flashback). There is nothing particularly mood-setting about this introduction until it is mentioned that a pirate treasure was buried, and that this was presided over by the Devil. This creates a mood of foreboding, because we know that the treasure was not only coming from a "sinful" origin, but that it is now directly entwined with the supernatural; we also assume that if the treasure is being shown to us, then it must appear again, boding ill for whoever encounters it.

The mood shifts as we are introduced to Tom and his wife, and the mood here is clearly a combination of disgust and pity. Their home is described as forlorn, sterile and unenviable, and their personalities as caustic and petty. We are being led to dislike them from the start, and perhaps the intention is to lead the reader to a mood of superior moral authority, in effect scolding the characters because we already have an idea of what's going to happen to them (something  bad), but knowing that they probably deserve it. 

This is an interesting question as often in pieces of literature the mood or feeling that a text creates varies as the plot progresses. This excellent short story is no exception. Note how the mood starts off by giving us a sense of the hardship and misery of Tom Walker through the use of such words as "forlorn," "alone," and "straggling." However, very quickly the mood changes to one of foreboding or oppression as Tom Walker voyages into the swamp:

Like most shortcuts, it was an ill-chosen route. The swamp was thickly grown with great gloomy pines and hemlocks, some of them ninety feet high, which made it dark at noonday, and a retreat for all the owls of the neighbourhood. It was full of pits and quagmires, partly covered with weeds and mosses, where the green surface often betrayed the traveller into a gulf of black, smothering mud...

Notice how the description and diction create this mood of fear and unseen danger.

You might want to consider how the mood continues to develop throughout the story, for example when Tom starts his work as a banker and lives a civilised life, away from the supernatural images of the swamp. However, I think the mood that dominates is one of supernatural terror and fear.