The supernatural appearance of the ghost on a chilling, misty night outside Elsinore Castle indicates immediately that something is wrong in Denmark. The ghost serves to enlarge the shadow King Hamlet casts across Denmark, indicating that something about his death has upset the balance of nature. The appearance of the ghost also gives physical form to the fearful anxiety that surrounds the transfer of power after the king’s death, seeming to imply that the future of Denmark is a dark and frightening one. Horatio in particular sees the ghost as an ill omen boding violence and turmoil in Denmark’s future, comparing it to the supernatural omens that supposedly presaged the assassination of Julius Caesar in ancient Rome (and which Shakespeare had recently represented in Julius Caesar). Since Horatio proves to be right, and the appearance of the ghost does presage the later tragedies of the play, the ghost functions as a kind of internal foreshadowing, implying tragedy not only to the audience but to the characters as well.
The scene also introduces the character of Horatio, who, with the exception of the ghost, is the only major character in the scene. Without sacrificing the forward flow of action or breaking the atmosphere of dread, Shakespeare establishes that Horatio is a good-humored man who is also educated, intelligent, and skeptical of supernatural events. Before he sees the ghost, he insists, “Tush, tush, ’twill not appear” (I.i.29). Even after seeing it, he is reluctant to give full credence to stories of magic and mysticism. When Marcellus says that he has heard that the crowing of the cock has the power to dispel evil powers, so that “[n]o fairy takes, nor witch hath power to charm,” Horatio replies, “So have I heard, and do in part believe it,” emphasizing the “in part” (I.i.144–146).
But Horatio is not a blind rationalist, either, and when he sees the ghost, he does not deny its existence—on the contrary, he is overwhelmed with terror. His ability to accept the truth at once even when his predictions have been proved wrong indicates the fundamental trustworthiness of his character. His reaction to the ghost functions to overcome the audience’s sense of disbelief, since for a man as skeptical, intelligent, and trustworthy as Horatio to believe in and fear the ghost is far more impressive and convincing than if its only witnesses had been a pair of superstitious watchmen. In this subtle way, Shakespeare uses Horatio to represent the audience’s perspective throughout this scene. By overcoming Horatio’s skeptical resistance, the ghost gains the audience’s suspension of disbelief as well.