The characters in this Verdi opera tend to have two names. This is due to its Italian libretto being based on a story set in Sweden, the action of which was transferred to seventeenth century America. As a result, Gustavus III of Sweden became the English Govenor of Boston, Richard Earl of Warwick. Though in Italian, of course, he's called Riccardo. To make things even more complicated, modern productions often revert to the Swedish setting.
The one character whose name remains constant is Amelia, the heroine. She is loved by the king, though she's married to his best friend. The king is warned by a fortune-teller that the next man to shake his hand will be the instrument of his death. And along comes his best friend and shakes it.
Amelia is a faithful wife. So she's horrified to find herself returning the king's love. The fortune-teller sends her to gather herbs by the scaffold. These are guaranteed to cure unwanted feelings. The king finds her there. Later her husband turns up. She is veiled and, at first, he doesn't recognise her.
On discovering that the veiled woman with the king was his own wife, Amelia's husband joins an assassination plot against him. Chosen to pull the trigger at a masked ball, he discovers the king's identity from a passing page and shoots him. The king dies beautifully, declaring Amelia's innocence and forgiving his enemies.
