Final answer:
In Act 1 of 'Hamlet', Marcellus, Bernardo, and Horatio encounter the ghost of the deceased King of Denmark while on patrol at the castle of Elsinore.
Step-by-step explanation:
In the opening scene of Act 1 of Hamlet, the characters Marcellus, Bernardo, and Horatio encounter a ghost. This spectral figure is especially unsettling because it bears the likeness of the recently deceased King of Denmark, also Hamlet's father.
The play begins with these soldiers on patrol at the castle of Elsinore, where they discuss the eerie appearances of this apparition. The implications of this ghost's visitation will profoundly affect the entire narrative, leading to explorations of revenge, sanity, and the nature of the unknown.