Problem solved. Measure for Measure is one of Shakespeare’s “problem plays,” troubling directors and scholars for four centuries, and each production, each reader, each audience arrives at its own interpretation. Charles McMahon has found one solution, and it’s brilliant.

The plot: the Duke (Anthony Lawton) has been a lax ruler, inclining more toward a bookish life than responsible governance, and as a result his city has deteriorated. Lawton gives us a Duke who is, initially, distracted, eccentric, and shy. He will eventually reveal his royal nature and take command both of his realm and the stage. He decides to disappear, and, as a way of righting the social balance, he leaves Angelo (Ben Dibble) to rule in his stead.

Angelo is a prude and a tyrant, “a man whose very blood is snow-broth,” so when he learns that Claudio (Chris Anthony) has a pregnant girlfriend, he decides to make an example of him and execute him for lechery.

The rest of the play is taken up with attempts to save Claudio’s life. His sister, Isabella (Claire Inie-Richards), a novice nun, pleads with Angelo, who then offers her a deal: your brother’s life for your virginity. Dibble’s transformation from a self-righteous prig to a man overtaken by lust and self-disgust is stunning.

Isabel is horrified and refuses to sacrifice her chastity. What a pair. Who better to tempt a puritantical prig than another one?

People are complicated, and nobody knew this better than Shakespeare. The Lantern cast of eight plays many roles; this is not merely thrifty, but also revelatory: When each actor reappears in a different costume as another person (the costumes designed by Janus Stefanowicz are superb), they are also revealing another self, another side of a personality.

Most impressive is Charlotte Northeast, who plays Mistress Overdone, a bawd; Elbow the policeman, who arrests Mistress Overdone; the prison’s Provost, who locks her up; as well as Angelo’s jilted virginal fiancée. Jered McLenigan is hilarious as the smarmy Lucio, and Kirk Wendell Brown and Adam Hammet round out this small but seemlingly enormous and excellent cast.

There is a stunning moment when Isabel says, “No” to Angelo and, when he persists, threatens to denounce him publicly. He replies with absolute and sneering confidence, “Who will believe thee, Isabel?” This is the power of the powerful. Anticipating the contemporary world, Shakespeare gives us the Renaissance equivalent of a hashtag conclusion.

THEATER REVIEW

Measure for Measure

Through April 21 at Lantern Theater Company, St. Stephen’s Theater, 923 Ludlow St. Tickets: $28-$43. Information: 215-829-0395, lanterntheater.org.