The anomalies of Measure for Measure which have caused it to be regarded as the paradigmatic 'problem play' spring from its swerve away from Whetstone's Promos and Cassandra. In the source play Cassandra, the sister of Andrugio, the young man condemned to death, is no devout novice in an austerely ascetic order, and therefore there is no barrier to her marriage with Promos, the Corrupt Magistrate, who has fallen in love with her, when matters are set right by the Beneficent Ruler in the end. There is no Mariana, no bed-trick, no plethora of severed heads - one (somewhat mangled and unrecognizable) serves perfectly adequately to provide for the deception of Promos and the escape of Andrugio - and no absconding Duke, setter-up of the delinquent Deputy in the first place. What has been gained, is the question that suggests itself, by the additional complications?

The Duke, watching events from the wings, returns in time to prevent the death of Claudio - the fatal error which would actualize the play's tragic potential - by having recourse to the repertoire of means whereby comedy, for its own eudaemonic ends, evades, circumvents, or surmounts the threats and dangers incipient in initial situations. But these 'theatregrams' as such modular manoeuvres have been called - benign deception or imposture, clownish interlopers or intermediaries, disguises and unmaskings - give rise to as many problems on the level of characterization as they solve at the level of plot.