All grown up at 18 years old, tonight the Pittsburgh New Works Festival starts its annual marathon of 12 new one-act plays, staging three each weekend over the next four weeks.

"It's a really exciting season, with a lot of the plays by some of our best returning playwrights," enthuses Susan Zimecki, secretary of the New Works board.

New this year are weekly opening night "Mingles" that invite audience members to mingle with performers and playwrights. Often thematically tied to one or more of that week's shows and sponsored by restaurants, they are all held at Open Stage.

Each show is produced by a different local theater company.

SEPT. 4-7

Judy McGee, "Johnny Quest and the Giant Kidney," about a serial killer who offers to donate a kidney to a young father of four. For The Theatre Factory, Scott Calhoon directs Daniel Franklin, Travis McGunigle and Kendra McLaughlin.

Cory Tamler, "The Funeral," set amid female captives outside the ruins of ancient Troy. For The Heritage Players, Carol Shafer directs Mary Romeo, Miranda Lane, Courtney Day Nassar, John Feightner, Kauleen Cloutier, Adrienne Elion and Sandy Boggs.

Brian Paul Robertson, "The Promise," about the visit of a soldier as the result of a pact made with his buddies in battle. For Apple Hill Playhouse, Katya Ramsey directs Mere Davis, Dan Shaffer, Phil Powell and Margie Hillebrecht.

The Sept. 4 Mingle is sponsored by longtime New Works participant Michael Moats, whose "Arriverderci, Al: Dinner with the Godfather," is playing at several venues.

SEPT. 11-14

Jacob Appel, "The Mistress of Wholesome," about couple hoping to adopt and the husband's mistress. For The Summer Company, Steve Fatla directs Thalia Snyder, Susan Moran and Allison Fatla.

James Sievert, "The Hope and Heartbreak of the Day Trader," set in Paris, advises, "Don't despair when you're down, and don't gloat when you're up." For mimeradio.org, Kathleen McKissock and lance-eric skapura direct David Santiago, Kelly Hardy Rogers and Anji Corley.

Chris Gavaler, "Man Woman/Hombre Mujer," is bilingual, set in a waiting room. For McKeesport Little Theater, Chuck Penick directs Trent Wolfred, Jessica Kennedy and Zilda Alvez. The Sept. 18 Mingle is sponsored by Mallorca, reflecting the Spanish theme of the third play.

SEPT. 18-21

F.J. Hartland, "Cemetery Plot," about a young man, troubled by the death of his mother, who may have the chance to remedy his guilt. For CCAC South, Lora Oxenreiter directs Grant Bojarski, Mary Beth Underwood and Dan Krack. This is Hartland's eighth play for New Works, a record.

Chris Biondi, "Only Lightning," set in a concert hall, coffee shop and apartment. For Gemini Theater, Todd Betker directs Brandi Welle, Rob Gorman and Diana Ifft.

Joanna Lowe, "Absence Makes the Eyes Grow Fonder," in which a man reflects on the not-so-nostalgic life of his eccentric wife. For Baldwin Players, Clyde Adams and daughter Ashley Adams direct Ruth Flaherty, Dennis Gills, Sean Butler and Meagan Reagle.

SEPT. 25-28

Robert Isenberg, "In Air," an unexpected run-in with an old friend on Capri. For Cup-a-Jo, Leah Klocko directs Shawn Smith, Laura Wagner and Heather Gray.

Margaret McClosky, "Old Head," about an American encountering a librarian in an Irish town. For Open Stage, Naomi Grodin directs Vince Ventura, Tara Lyn Zynel and Jody O'Donnell.

Alex Goldberg, "The Third Date," in which Bradley receives a surprise visit from his father. For Rage of the Stage Players, Joseph A. Roots directs Pete Fernbaugh, Bethany Vahabzadeh and Thomas David Sterner.

Inspired by the Irish theme of "Old Head," the Mingle will be sponsored by Mullaney's Harp & Fiddle Irish Pub.