The Tragedy of Hamlet, Prince of Denmark — Act 1, Scene 5: Another part of the platform.

On the platform, the ghost leads Hamlet aside and reveals that it is his father’s spirit, condemned to wander at night and suffer in fire by day. It says that Claudius poisoned him while he slept in the orchard, then took his crown and his wife, Gertrude. The ghost demands revenge but tells Hamlet not to harm Gertrude, leaving her punishment to heaven. After the ghost departs, Hamlet vows to erase everything else from his memory and remember only this command. Horatio and Marcellus return, and Hamlet makes them swear not to reveal anything they have seen or heard. He then tells them he may act strangely and leads them off.