In the most high and palmy state of Rome,
A little ere the mightiest Julius fell,
The graves stood tenantless, and the sheeted dead
Did squeak and gibber in the Roman streets.

– William Shakespeare

Hamlet, Act 1, Scene 1. Horatio to the guards after the sighting of the Ghost. He is pointing to the seriousness of the sighting, recalling that before Caesar died the dead rose from their graves and were in the streets. This foreshadows the revenge that Hamlet will embark upon, leading to the death of his uncle, mother and himself.