1. Scene 5 is possibly the most important plot development during the first Act. The ghost of young Hamlet's father, after luring him away from Marcellus and Horatio, tells young Hamlet of his uncle's betrayal and murder of the king. He also commands Hamlet to seek revenge on his uncle but leave his mother alone. The scene sets up the plot for the rest of the drama.
2. The play truly could not go on without this scene as it is the first time the ghost speaks and the first the audience actually knows (maybe not thinks) of the treachery committed by Hamlet's uncle.
3. My question is: What's up with the ghost? It only speaks to Hamlet, even though telling Horatio or Marcellus of the uncle's deed would strengthen Hamlet's revenge scheme. Also, if the ghost is dressed for battle and can speak to mortals, why can't he himself take revenge on his brother? At least haunt him a little?
