A Christmas Carol has for its protagonist the miser Ebenezer Scrooge, owner of a counting house and employer of the poor Bob Cratchit, his clerk. Scrooge saves on everything, so in winter, at Christmas, the office is warmed only by the smallest fire. To Scrooge, this is no matter, since his inner coldness is constant, and other people's comfort is unimportant to him. When his nephew appears to wish him a merry Christmas, Scrooge sneers at his sentimentality.
He allows his clerk a day off at Christmas, but only on the condition that he should arrive early the day after. Locking up the office, Scrooge heads for his own rooms, which once belonged to Jacob Marley, his partner, who died seven years ago. Arriving at the door, he receives a first shock; the door-knocker is suddenly, inexplicably transformed into his dead partner's face, staring at him. The vision passes, and Scrooge bolts the door from the inside. Sitting down in front of the dying embers on the hearth, Ebenezer Scrooge is subjected to the second portent, the ringing of all the bells in the house. Someone or something is trying to get in touch with his frozen soul.
As it turns out, it's his dead partner who finally materialises, right through his own door, laboriously dragging a chain of cash boxes, keys, ledgers, and similar paraphernalia after him. When the ghost sits down in front of him, Scrooge has to admit that it's actually his old partner he is talking to. The apparition's next step is to explain his present condition to the miser; since Marley himself lived on the same basic principle as does Scrooge, he is in a very good position to demonstrate to his former partner what the afterlife is like for one who has never done a good deed to his fellow man.
There is one way out of this misery for Scrooge, though; it is possible to mend one's ways and cleanse one's conscience. To amplify the message, three spirits will visit shortly: an hour after midnight on the following three nights. Having delivered his message and his warning, Marley goes away, dragging his chain.
Strangely, Scrooge manages to fall asleep, but is awakened when the clock strikes midnight. One hour later he is visited by the Ghost of Christmas Past, an apparition with a child's face, long, white hair, and a full-grown body. It makes Scrooge an offer he can't refuse: to go on a sentimental journey to his own past.
Negotiating time and space effortlessly, they arrive in time to see the small boy Ebenezer, a lonesome child with books for his only friends. Next, he sees his beloved sister come to bring him home from school at Christmas, and is reminded that this very sister - who died young - had a son; the very same nephew who looked in on him the day before to wish him merry Christmas. Lost love, lost comradeship, and lost chances for happiness are shown in rapid succession, and then the exhausted Scrooge is dropped of at home, where he dozes off.
The following night verges on Christmas morning, so the Ghost of Christmas Present gets an opportunity to show Ebenezer the merrymaking of ordinary people. They spy on Bob Cratchit, who makes the most of his meagre resources in the bosom of his little family, carrying his son Tim, who is weak of health, and lighting the meagre meal with his inner warmth and generosity, demonstrated when he proposes a toast to his mean employer, gently upbraiding his wife, who is unable to adopt a generous attitude towards Scrooge.
After some sightseeing among the merry holiday-makers of the city, Scrooge is brought to the home of his nephew, where his generous relatives drink the miser's health. He seems to have not an enemy, no reason to close himself off from humanity.
The last ghost, that of Christmas Future, arrives, to show him the emptiness of temporal life. A peek into the future shows thieves plundering a dead man's belongings. He even gets a glimpse of himself, lying dead, and retreats in horror. The final blow is dealt to his the weakened armour of his soul when he learns that Tim Cratchit has died.
The vision of himself dead, his own neglected grave, all this prompts Ebenezer to beg for mercy. Waking as from a nightmare, he thanks Jacob Marley's ghost for this second chance, and he really changes. He gets a huge turkey for the Cratchit family, makes large contributions to the poor, and turns up at his nephew's a changed man, filled with the merry spirit of Christmas. The spirits of Christmas had served their purpose, and Jacob Marley had done his good deed. For the rest of his life, Ebenezer Scrooge was a good generous man, living the spirit of Christmas.