The duke, on his entry, is met by Isabella, who accuses Angelo of violating her chastity. She is arrested for slander. Mariana claims Angelo as her husband. Angelo protests his innocence until the duke, who re-enters disguised as the friar, is stripped of his friar’s hood by Lucio. Angelo then confesses his crimes, and is sentenced first to marry Mariana and then to be executed for Claudio’s death.
Mariana begs for Angelo’s life and persuades Isabella to join in the plea, despite Claudio’s death. Isabella begs the duke to spare Angelo. The duke refuses and has Barnardine and another prisoner brought in. When this second prisoner is unmuffled, he is revealed to be Claudio. Angelo’s death sentence is revoked, Lucio is sentenced to marry Kate Keepdown, and Claudio is instructed to marry Juliet. The duke offers his hand in marriage to Isabella.