1. Hamlet becomes sad after his father's mysterious death and his mother's quick marriage to his uncle Claudius, who becomes the new king. Hamlet sees his father's ghost, which tells him that Claudius murdered him.
2. Hamlet pretends to be mad to avoid suspicion as he plots his revenge. He asks players to perform a play mimicking Claudius's crime to confirm the ghost's story.
3. During the play, Claudius's reaction convinces Hamlet that the ghost told the truth. Hamlet is now certain Claudius killed his father and plans to take his revenge.