The opening act of Hamlet foreshadows the drama and suspense of the whole play. For instance, we know that there is impending war with Young Fortinbras, that King Hamlet is dead. We know that the Ghost has appeared more than once. THe mood of the opening scene is one of fright and confusion, something that will pervade throughout the play. THese factors set the mood, foreshadowing that this will not be a comedy, as well as letting the reader know that everything that Bernard and his friends mention will be important throughout the body of the play