Measure for Measure is a problem play, because it is neither comedy nor tragedy. It had the Duke leaving the kingdom in charge of Angelo, who is a strict moralist. He insists on the death penalty for sec outside marriage, sentencing Claudio to death for getting his lady pregnant. Claudio begs his sister Isabella, a novice nun, to plead for his life, and when Angelo insists on sleeping with her as the price, Claudio begs her to do it.
The Duke in disguise helps Isabella swap with Angelo’s jilted lover on the night, but Angelo reneges on the deal, despite being taken in. The Duke returns and exposes Angelo, forcing him to marry his former love. Claudio is reprieved and it is implied that Isabella marries the Duke. It is my favourite play.