What mood is stressed at the outset of the play?
A mood of deep unease and foreboding permeates the opening of the play. Francisco, the sentinel being relieved of duty, sets the tone when he says:
'Tis bitter cold,And I am sick at heart.
Horatio interprets the ghost as more than merely a personally frightening apparition. He perceives it as an ill-omen: "This bodes some strange eruption to our state," he says. Later, he will add to the tone of unease and foreboding by saying:
A little ere the mightiest Julius fell,The graves stood tenantless and the sheeted deadDid squeak and gibber in the Roman streetsAs stars with trains of fire and dews of blood,Disasters in the sun, and the moist starUpon whose influence Neptune’s empire standsWas sick almost to doomsday with eclipse.
And why such daily cast of brazen cannonAnd foreign mart for implements of war.
The mood is tense and suspenseful in Act I of the play. The ghost appearances leave everyone with a different interpretation for the ghost's arrival, yet none of them are of a positive nature. Hamlet is the only one privy to the ghost's need for vengeance.
Hamlet is also presenting tense and mysterious behavior. His mother speculates it is from his father's death and Claudius is suspicious of it, as well, but for different reasons. Hamlet is contemplating the actions he will take, yet he has not yet committed to act on the ghost's words.
This creates the suspenseful tension that sets us up for the coming events. Although the suspense of Hamlet's inaction will last most of the play.