When the Duke of Vienna takes a mysterious leave of absence and leaves the strict Angelo in charge, things couldn't be worse for Claudio, who is sentenced to death for fornication. His sister, Isabella (a nun-in-training), however, is a very persuasive pleader. She approaches Angelo, but instead of offering clemency, Angelo offers to save Claudio's life if Isabella sleeps with him. The only sympathetic friend Isabella has is a priest who, in reality, is the Duke in disguise - and he has a plan.