What happens when a government sets out to vanquish the moral decay of society, only to discover that the greatest corruption lies within its own ranks?

That is the all-too-timely question that will be explored in "Measure for Measure," William Shakespeare's 400-year-old tale of what happens when righteousness faces down justice and virtue encounters vice. The Yale Repertory Theatre and the School of Drama have joined forces to stage a special production of the classic comedy, which will feature the graduating acting class. The show will run Jan. 28-Feb. 20 at the Yale Repertory Theatre, corner of Chapel and York streets.

"Measure for Measure" begins when the Duke of Vienna commissions the puritanical Angelo to rid the city of rampant decadence. The first miscreant to run afoul of the new regime is Claudio, whose sister, the nun Isabella, comes to plead for her brother's life. Enamoured by the beautiful young woman, Angelo tells Isabella that he will put her brother to death unless she sacrifices her religous beliefs and agrees to become his lover.

The play will be directed by Mark Rucker, an 1992 alumnus of the School of Drama. "I'm delighted to be returning to the Yale School of Drama to once again direct the graduating acting class," says Rucker. "Not only are they a talented class, they also work well as an ensemble, having already been together for two-and-a-half years. Their immediate knowledge of each other is a director's gift that I don't usually see in regional theater, where casts come together from all over the country."

Rucker is an assocate artist at South Coast Repertory, where he directed such shows as "Dimly Perceived Threats to the System," "Our Town," "The Birds" and the world premiere of "So Many Words" by Roger Rueff. He has directed many productions at regional theaters, most recently "How I Learned to Drive" and "The Taming of the Shrew" at Seattle's Intiman Theatre, the premiere of Anna Deveare Smith's "House Arrest" at Arena Stage, and "The Model Apartment" at La Jolla Playhouse. Rucker previously staged the Yale Rep productions of David Mamet's "The Cryptogram," John Guare's "Landscape of the Body" and Shakespeare's "Twelfth Night."

Stan Wojewodski Jr., dean of the School of Drama and artistic director of the Yale Rep, says: "Newcomers to the theater will find out what our core audience already knows, that Mark is an extremely versatile director whose work places visual and emotional strength -- and a great sense of humor -- at the service of the text."

The cast for "Measure for Measure" includes Claudia J. Arenas, Ed Blunt, Adrienne Carter, Esther K. Chae, Chris Henry Coffey, Daniel Cooney, Adrienne Dreiss, Jon Eklund, Rodrick Fox, Joanna Glushak, Jim Hart, Austin Jones, Adrian LaTourelle, Joey Parsons, Heather Anne Robinson, Grama Shiels and Paul Tigue.

The design team for the production includes scenic designer Rachel Nemec, costume designer Lora Dole, lighting designer Scott Zielinski and sound designer Shane Rettig. The production dramaturgs are Anne T. Davison and Sean Libby.

Tickets for "Measure for Measure" range from $26 to $33. Group discounts and subscriptions are also available. To purchase tickets, call the Yale Rep box office at 432-1234. The box office is open 10 a.m.-6 p.m. weekdays and Saturdays, and until show time on performance dates.