The ghost of the murdered Don Andrea and the figure of Revenge form the chorus in The Spanish Tragedy. They comment on what is happening throughout the play and remind the audience of the need for vengeance.

The play opens with a prologue in which the Ghost of Andrea tells the story of going to Hades after his death. It is uncertain to the occupants of the Underworld whether he belongs in the fields of the lovers, as he is a lover, or in the field of slain warriors, as he is a warrior. Prosperine, queen of Hades, decides to send him back to earth as a ghost, and Revenge tells him that justice will unfold. Revenge imparts the following information to both Andrea and the audience:

thou shalt see the author of thy death,
Don Balthazar, the prince of Portingal,
Depriv'd of life by Bel-imperia:
Here sit we down to see the mystery,
And serve for Chorus in this tragedy.

At the end of each act, the Ghost of Andrea laments the injustices that have occurred. For example, at the end of act 1, he says to Revenge,

Come we for this from depth of under ground,—
To see him feast that gave me my death's wound?
These pleasant sights are sorrow to my soul:
Nothing but league and love and banqueting!

Revenge assures him, however, that he brings pain and misery to Balthazar and the others who deserve it. In the end, it is not their untimely deaths that are the true tragedy, but the suffering, as Revenge points out, that they will endure in Hades.