Dickens uses foreshadowing to hint at the story's forthcoming supernatural events. The narrator's emphasis on death in the first stave signals Marley's imminent return:
Marley was dead: to begin with. There is no doubt whatever about that . [...] You will therefore permit me to repeat, emphatically, that Marley was as dead as a door-nail.
The narrator repeats the fact that Marley is dead "emphatically" and uses the same simile multiple times. He even sounds nervous, as if he is trying to reassure himself that Marley is dead. This creates a sense of foreboding and suggests that everything will not remain as it initially seemed.
With this in mind, Marley's appearance is all the more meaningful because the narrator has taken pains to establish that he's dead—and not just that he's dead, but that he's very dead; as "dead as a door-nail." The emphatic comparison of Marley to a doornail and Scrooge's certainty that he is dead ultimately combine to create a moment of delicious situational irony. when he eventually reappears. Everyone believes that Marley is dead, and the text spends a ridiculous number of words insisting that he will never come back to life, but he does indeed return in the following scene.
Scrooge spends much of the text begging to return to reality, and yet during his encounter with the Ghost of Christmas Present, he begs to continue the dream:
The Ghost was greatly pleased to find him in this mood, and looked upon him with such favour that he begged like a boy to be allowed to stay until the guests departed. But this the Spirit said could not be done.
In this scene, Scrooge actively participates in games at a party with his family. He is compared to a "boy," which indicates that a partial transformation has taken place. He begins to take on some of the positive characteristics of a child as his miserly gruffness is replaced by youthful energy. The Ghost, who strives to teach him a lesson about the importance of generosity and goodwill, takes pleasure in watching Scrooge enjoy the scene. This moment is an ironic reversal of the second stave, in which Scrooge begs to go home and the ghost insists he stay and learn his lesson. Throughout the story, Scrooge becomes more amenable to learning lessons from each spirit. Moments like this have definite ironic tension; Scrooge used to act grumpy and awful, but now he unexpectedly begins to realize the consequences of his attitude.