Something is rotten in the state of Denmark.

This line is spoken by Marcellus in Act I, scene iv (67), as he and Horatio debate whether or not to follow Hamlet and the ghost into the dark night. The line refers both to the idea that the ghost is an ominous omen for Denmark and to the larger theme of the connection between the moral legitimacy of a ruler and the health of the state as a whole. The ghost is a visible symptom of the rottenness of Denmark created by Claudius’s crime.