ANTONIO: Then, tell me,
Who’s the next heir of Naples?
SEBASTIAN: Claribel.
ANTONIO: She that is queen of Tunis; she that dwells
Ten leagues beyond man’s life; she that from Naples
Can have no note, unless the sun were post –
The man i’ the moon’s too slow – till new-born chins
Be rough and razorable; she that – from whom?
We all were sea-swallow’d, though some cast again,
And by that destiny to perform an act
Whereof what’s past is prologue, what to come
In yours and my discharge.
– William Shakespeare
The Tempest, Act 2, Scene 1. Antonio tells Sebastian that the events caused by the tempest have given them the opportunity to "perform an act." The past and what’s happened so far is the prologue of the play, while the script is very much in their own hands – "yours and my discharge." The act Antonio is talking about is that they murder Sebastian’s brother Alonso and steal his crown. Sebastian’s sister Claribel is too far away in Tunis and will have no say. There is good use of theater metaphor in this passage.