Angelo is the deputy to Vincentio, the Duke of Vienna, who begins the play by departing the city under mysterious circumstances and leaves the strait-laced Angelo in power. Angelo's first act is to begin the enforcement of an old law that makes fornication out of wedlock punishable by death, but proves himself a hypocrite when Isabella, the sister of Claudio, the first man sentenced under the law, comes to plead for her brother's life. Angelo agrees to commute the sentence only if she will sleep with him. Angelo is ultimately duped by being set up with Mariana, a woman he was once betrothed to, who masquerades as Isabella at the assignation. And after Angelo thinks he has attained the object of desire, he covers his tracks by ordering the execution of Claudio after all. But before the scheme is revealed to him, he admits his angst over his behaviour:
"This deed unshapes me quite, makes me unpregnant
And dull to all proceedings. A deflower'd maid!
And by an eminent body that enforced
The law against it! But that her tender shame
Will not proclaim against her maiden loss,
How might she tongue me! Yet reason dares her no;
For my authority bears of a credent bulk,
That no particular scandal once can touch
But it confounds the breather. He should have lived,
Save that riotous youth, with dangerous sense,
Might in the times to come have ta'en revenge,
By so receiving a dishonour'd life
With ransom of such shame. Would yet he had lived!
A lack, when once our grace we have forgot,
Nothing goes right: we would, and we would not."