Salter (D.W. Jacobs) and his son B2 (Francis Gercke) sit on a worn brown leather sofa speaking around and at each other in fits and starts, unfinished sentences, uncompleted thoughts. They seem not so much angry as agitated.

The son asks about the circumstances of his birth. Slowly it becomes clear: B2 is a clone, and what’s worse, the doctor cloned not just the one requested by Salter, but “a number” of others as well (including B2’s clones Bernard and michael Black.)

Caryl Churchill’s one-act play, A Number, is in its San Diego premiere through June 29 at Cygnet Rolando Theatre, directed by Esther Emery.

“How many of these things are there?” Salter asks.

“You called them things,” says B2. “I think we’ll find they’re people.”

The number 20 is mentioned.

“I wonder if we can sue,” muses Salter.

“Sue? Who?” asks B2.

Salter is visited by three of his “sons” in five separate scenes, two of whom want to know why he treated them the way he did. B2 is more puzzled than anything; Bernard is furious, with barely-concealed violence that explodes in one scene.

Truth may be the biggest casualty in these encounters. Salter, clearly being destroyed by guilt and the enormity of the unintended consequences of his action, tries any answer he thinks will appease the son at hand; if that doesn’t work, he floats another explanation.

The last son to appear is Michael Black, mathematics teacher, father of three and, unlike the others, of sunny disposition and positive outlook. To Salter’s despair, this son can’t be explained by bad genes, therefore … but the alternative is too damning to contemplate.

A Number was written in 2002, during the flap over the cloning of Dolly the sheep. But science marches on, and in January of this year a local firm announced the successful cloning of a human embryo by somatic cell transfer (see www.stemagen.com for more information).

A Number is another directing triumph for Emery, who had an E.E. Cummings-like script and almost no stage directions to work with. She’s made dramatic sense of this dense and important play with the able help of Jacobs and Gercke, who have the requisite splendid timing and play well off each other. Jacobs is solid – and sad – as the father whose desire for a second chance at parenting went horribly wrong. Gercke’s tour de force performance as all three sons is a pleasure to watch.

The questions raised by this 60-minute play – nature vs. nurture, the ethics of cloning for any reason, the unintended consequences of scientific research – provide enough food for thought and discussion that Emery has suggested the second act should take place in the car on the way home. Sounds like a good idea.

A Number plays through June 29 at Cygnet Rolando Theatre. Shows Thursday through Saturday at 8 p.m.; Sunday at 2 and 7 p.m. For tickets call 619-337-1525 or visit www.cygnettheatre.com.

Heels clicking on sidewalk signal her return from work. She opens the door of her postage stamp-sized efficiency apartment and prepares for another solitary evening in her impossibly orderly home, neatly hanging suit jacket, placing shoes in the rack, carefully setting the table with place mat, smoothing the cloth napkin, placing the flatware.

Ms. Rasch (Linda Libby) speaks not a word and allows only two sounds this night: a TV infomercial which she switches off within a minute or two, and a radio announcer (J. D. Steyers), who emcees a classical Request Programme of pieces dedicated to lovers and friends.

ion theatre presents German playwright Franz Xaver Kroetz’s 90-minute solo piece through June 14 at the Lab at the Academy of Performing Arts in Mission Valley. Glenn Paris directs.

Her demeanor changes with the program. She seems to absorb energy through the radio waves, nodding a bit to the rhythm, even puffing her cigarette with more vigor.

But too soon the program is over, and she returns to her world of ritual. She cleans obsessively – the sink, the toilet, anything she touches. On the sink, her arsenal of lotions and salves line up with kitchen cleaning products. Nothing is allowed to be out of place.

Matt Scott & Claudio Raygoza’s cramped set and Brylan Ranscht’s stark lighting add physical claustrophobia to Ms. Rasch’s already boxed-in psyche.

Kroetz, known as one of Germany’s most controversial and original experimental playwrights, specializes in portraying the bleakness of working-class existence. Loneliness and isolation are his norms; suicide sometimes a welcome option.

When the program is over, she turns her attention to a rug-hooking project, which she approaches with the same grim determination that seems to rule the rest of her life. Her face darkens a bit as she considers a stitch that may be, dare I say it, less than perfect, then puts the project way and prepares for bed.

Request Programme is grim, interior theater, definitely not for the Neil Simon crowd or those expecting a traditional play. It may require more of you than you are willing to give. But if on-the-edge experimental theater is your bag, don’t miss this production and Libby’s stunning performance.

Request Programme plays through June 14 at The Lab at the Academy of Performing Arts. Shows Friday and Saturday at 8 p.m.; Sunday at 7 p.m. For tickets call 619-374-6894 or visit www.iontheatre.com.

When you enter the theater, you’re handed a one-sheet welcoming you as a potential backer of “the greatest Broadway musical of all time,” a 12-hour extravaganza recalling the history of the world. This is a backers’ audition, and writers Jed Feuer (Andrew Ableson) and Boyd Graham (Omri Schein) are here to give you the highlights of The Big Bang (through June 22 at North Coast Repertory Theatre) and hope you’ll open your heart and checkbooks. (You’ll get a program as you leave.)

Rick Simas directs this musical skip through world history, lampooning musical comedy as much as history itself. Ableson and Schein are accompanied by the most excellent pianist Albert (Steven Withers).

Ableson and Schein use ingenious costumes and sometimes questionable taste as they tromp through the garden of Eden (Eve: “I think he’s cheating on me with a chimp!”), Egypt and Rome, then goes on to cover the birth of Christianity, Columbus, Henry VIII, the American colonies, Napoleon’s France, the Antebellum South, the Irish potato famine, Tokyo Rose, Shanghai Lil and Eva Braun, on the way to Woodstock, where they run out of time.

Nineteen goofy songs enliven this twisted look at history, in which Mafiosi warn Caesar about the Ides of March: “Wake up, Caesar, you’re the wop they wanna whack!”

Later Mary explains to Mrs. Gandhi that “being God’s mother is a helluva job.” Mrs. Gandhi has her own concerns: “My son still wears a diaper.”

One of the best bits is the cross-dressing Nefertiti with trash can headdress and bellows pendant, stretched out on a red couch: “I’m a diva, honey. King Tut? King Butt!”

And Leo the lion, in his dressing room before the next Colosseum (spelled wrong in the program) show: “I wouldn’t pay a nickel to see a Christian eat a lion. But they wanna see me chompin’ on a screaming holy roller.”

Frat boy humor? You bet. Tasteless? Yep. But I can almost guarantee you’ll laugh. A lot.

Special kudos to Bonnie Durben, whose terrific props and set dressing keep the laughs coming almost as much as the songs.

The Big Bang plays through June 22 at North Coast Repertory Theatre. Shows Wednesday and Sunday at 7 p.m.; Thursday through Saturday at 8 p.m.; matinees Saturday and Sunday at 2 p.m. For tickets call 858-481-1055 or visit www.northcoastrep.org.