The duke, seeking refuge at a monastery, explains his purpose to Friar Thomas. Having led Angelo and his people to think he has gone to Poland, he now wishes to disguise himself as a friar in order to go unrecognized among his subjects. He has allowed the "strict statutes and most biting laws, / The needful bits and curbs to headstrong weeds" (I. iii. 19-20) to go unenforced over a period of several years. The laws have been openly flaunted and must now be brought to bear. When the friar gently suggests that it is for the duke himself, rather than his deputy, to do so, the duke agrees. However, since the fault is his for allowing the people too much scope, he feels it would seem "too dreadful" in him to turn suddenly strict. For this reason, he has deputized Angelo. He now wishes to observe his deputy's rule. As the scene closes, the duke implies that, having reason to doubt Angelo's character, he has made this a sort of test.
In a convent of the sisterhood of Saint Clare, Isabella is about to take her vows. She is interrupted in a conversation with Sister Francisca by a man's voice outside. The nun leaves Isabella to open the door to Lucio, who has come to tell her of Claudio's plight. Although at first she doubts her ability to sway Angelo's judgment, Lucio convinces her to go to him and plead for mercy.
