What is the first reference to the ghost in Hamlet?
The first reference to the ghost is in line 28 of the first scene of the play. At this point, Marcellus, who has just arrived with Horatio to stand guard outside the palace with Bernardo, asks Bernardo if "the thing" has "appeared again." It emerges that the ghost has appeared to Bernardo twice in recent nights, and that Marcellus, who has witnessed it as well, has brought Horatio along to see if it will appear in his presence. Horatio is a skeptic, claiming that the ghost will not appear, and when it actually does, he is dumbstruck, filled with "fear and wonder." It is apparent that Marcellus wanted Horatio to come along because he is an educated man (and perhaps because he is a friend of Hamlet,) because when it appears, Marcellus asks Horatio to speak to it, as he is a scholar. The men are trying to make sense of what they are witnessing, and they seem to value Horatio's opinion on the matter.