Five Hysterical Girls Theorem: math teeming photo: Jamey O’Quinn Our Lady of Sligo By Sebastian Barry Irish Repertory Theater 132 West 22nd Street 212-727-2737 The Five Hysterical Girls Theorem By Rinne Groff The Connelly Theater 220 East 4th Street 212-358-3657 more theater most popular most commented Stitching: Mission Abort by Alexis Soloski Palace of the End: Leash Fatigue by Alexis Soloski The Flat Earth Glows Sightlines by McCann, Ruth Bash'd!: Rap, Now Even Gayer Sightlines by ROB KENDT Misha Shulman's Brunch at the Luthers Sightlines by GARRETT EISLER Trash Talking With Harvey Weinstein by Tony Ortega Coming and Then Licking It Up. Is This a Gay Thing? Savage Love by Dan Savage At Home With Competitive Swallowers Crazy Legs and Eater X by Andy Kropa Gene Simmons and the Whores He Admires La Dolce Musto by Michael Musto Columbia's Knotty Noose Problem by Graham Rayman The 'W.' Stands for 'War Criminal' (17) Nat Hentoff Scientology's Crushing Defeat (14) Tony Ortega Runnin' Scared: From Brooklyn, a Rap Campaign Against Tight Clothes (9) Runnin' Scared: Arcynta Ali Childs Runnin' Scared: The City Pitted Kids Against Artists in the East Village (6) Runnin' Scared: Chloé A. Hilliard Savage Love: My Boyfriend Almost Fathered a Lesbian Couple's Baby?!? (5) Savage Love: Dan Savage

Sinéad Cusack has already garnered a U-Haul's worth of international awards for her portrayal of Mai, the 53-year-old lady of Sligo, who relives the story of her alcoholic life from a Dublin hospital bed. Morphine is her Proustian madeleine, though a pint of Guinness probably would have served just as well. It's a remarkable performance, though not in the tour de force fashion the reviewers have led one to believe; Cusack is too scrupulous an artist for that. Her quiet honesty is evident both in the way she re-creates the fullness of Mai's bitter suffering and in her unflagging effort to make the character's often stiltedly literary monologues sound natural. As demanding as the role is, however, it doesn't provide Cusack much opportunity to feed off the energy of her supporting cast. It's a one-person show superfluously surrounded by four other actors.

Mai is in the late stages of liver cancer, suffering from "claws" of pain in her back and rancorous feelings in her heart. Her husband, Jack (Jarlath Conroy), a would-be gentleman who served as an engineer in the British army, tries to console her, but his words only fuel her recriminations. Mai's resentment is provoked in large part by their changing social circumstances. While the play is set in 1953, it harks back to the upheaval wrought more than 30 years earlier by the Irish independence movement, which was as punishing to the big-house Catholic bourgeoisie (to which Mai was born) as it was to the Protestant Ascendancy. Mai's sense of dislocation, further compounded by drinking and the death of their son, transforms her from a young lass "lying in that comfortable old-country bedspread" to a brawling "demon" too depressed to give a damn about her family.

Director Max Stafford-Clark's production elicits decent enough performances from the do-little ensemble, notably Andrea Irvine as the saintly hospital nurse and Sinéad Colreavy as Mai's put-upon daughter. But the evening belongs to Cusack, who deserves a character as real and unwieldy as this one—only in a play that's more than a string of retrospective soliloquies.

The antic dramatic structure of Rinne Groff's The Five Hysterical Girls Theorem couldn't be more removed from the staid procedures of Our Lady of Sligo. Which isn't to say that Groff is more successful in realizing her vision. What her play demonstrates, however, is breathtaking ambition and kaleidoscopic style. Even at its messiest, there's something invigorating about it all—not easy given that the subject matter ranges gleefully from abstract algebra to number theory.

The action takes place at a seaside resort in turn-of-the-century England, the site of an international math conference. Moses Vazsonyl (Steven Rattazzi) is the reigning genius, a man who has already proven the existence of real numbers and who's determined now to discover the fifth in a series of prime numbers made up solely of 3s and 4s. A degree in higher mathematics, however, isn't an audience prerequisite, as the playwright is more interested in the nature of creative inspiration. Moses's compulsive problem solving is, after all, as mysterious—and competitive—as any artistic undertaking. Its ultimate value, too, may also be as subjective, as new theories arise, like plays, to eclipse older ones.

The drama's swirling chaos comes replete with subplots involving the affairs of Moses's randy wife, the fates of his unbalanced daughters (one of whom may be even better at numbers than her father), and the stolen notebooks of a self-taught young man, who provides Moses with the calculations needed to win further acclaim for himself. David Herskovits's direction, while making lively use of the cavernous Connelly Theater, can't resist putting auteur fingerprints on an already smudgy dramatic design. The glaringly uneven ensemble (of 18 actors!) makes sorting out the characters (a few of whom are given the same name) difficult enough, but when taped porno moans and wry stagehand asides are introduced the effect is like splashing paint on an already cluttered abstract canvas. Still, there's something infectious about the rapid pulse of the work, which sustains its tempo even when the action routinely trips on its own abstruse cleverness.