One of Shakespeare's "dark comedies," Measure for Measure is as noteworthy for its fascinating political and social implications as for its compelling characters: a duke masquerading as a monk, a would-be nun ordered to sacrifice her chastity to save her brother's life, and a self-righteous courtier, professing his incorruptibility while concealing a depraved private life. In this engrossing drama set in 16th-century Vienna, Duke Vincentio attempts to enforce the city's long-ignored morality laws, which results in a death sentence for Claudio, a young man accused of seducing and impregnating his fiancée. Isabella, his sister, attempts to gain a pardon for him, but refuses when she is asked to exchange her virtue for her brother's life. Claudio eventually is freed and utter tragedy is averted, as Shakespeare explores with force and sensitivity the basis of good government, public and private morality, and the balancing of justice and mercy, among other themes.