Hamlet devises a test to see whether Claudius is guilty: he hires a group of actors to perform a play about the murder of a king in front of the royal court, and has Horatio gauge Claudius' reaction. Claudius demands the play be stopped half through because it causes him to experience guilt. When Claudius leaves the on stage "audience" deeply upset, Hamlet knows that the ghost was telling the truth. He follows Claudius into his chambers in order to kill him, but stops when he sees his uncle praying; he does not want to kill Claudius while he is in a state of grace because Hamlet wants Claudius to suffer in purgatory and Claudius has just attempted to cleanse his sin through confession. A second attempt on Claudius' life ends in Polonius' accidental death.