Vincentio, Duke of Vienna, departs from his kingdom suddenly and inexplicably, resigning power to his deputy Angelo in his absence. Under Angelo's rule, a vigorous campaign against lechery and sexual license begins.
It seems that love is no defence under the newly-fortified laws and one of the first to suffer is Claudio, arrested and sentenced to death for making his lover, Juliet, pregnant before making her his wife.
In desparation, Claudio sends for his sister Isabella, hoping that her virtuous pleading can move the rigid Angelo to repeal his sentence. but when Angelo demands a higher price than Isabella is prepared to pay, it becomes evident that not only love but justice is at risk.
The Duke returns disguised as Friar Ludovcio, but will he intervene to spare his people from the not-so-upright Angelo, and how can he respond when young lovers are imprisoned alongside brothel keepers and bawds?