FERDINAND: This is strange: your father’s in some passion
That works him strongly.
MIRANDA: Never till this day
Saw I him touched with anger so distempered.
– William Shakespeare
The Tempest, Act 4, Scene 1. Ferdinand remarks about Prospero’s strong mood and Miranda tells him that she has never seen her father in such an angry state. Their puzzlement is an example of dramatic irony. Prospero’s anger is over the treachery plotted against him by Caliban with the aid of co-conspirators Stephano and Trinculo – which the audience already knows, but the young couple do not.