Summary of Hamlet act one scene one

The play opens in a cold noght outside a palace. There is a changing of gurards; Banardo replaces Francisco. After that Horatio and Marcellus arrive in the scene. They say they have seen the ex King of Denmarks spirit. On the third night, they let Horatio join them on their night shift to witness the spirit as it only appears in the scene at one o clock in the morning. Horatio doutbs the ghost will appear and doesnt believe it exists however suddenly it does. The ghost quickly dissapears straight after it arrives, they follow and violently approach the spirit when it re appears however it gets offended and disappears. Finally they all decide as a group to tell Hamlet the old Kings son about the appearence of his spirit so they do.