BAILEGANGAIRE, Irish Repertory, at Victory Gardens Theater. If Tom Murphy’s formulaic 1985 drama had a significant hand in reviving contemporary Irish playwriting, as some critics insist, then Irish stages must have been an utter wasteland. Young but bone-dry Mary is trapped in a rural thatched home caring for her senile grandmother, Mommo, a once renowned storyteller who now babbles incessantly a tale she never finishes. Occasionally Mary’s polar-opposite sister, Dolly, drops by on her motorcycle to chat before heading out on anonymous sexual romps. Once the family’s schematic dynamics are established, Murphy lets Mommo rattle on incomprehensibly for the better part of an hour while Mary frets and worries. Then, in the second act, he finally makes things happen to the characters, but their confessions and transformations are mostly the artificial kind that playwrights like to foist off on their creations.

Director Kay Martinovich’s gentle touch gives the evening warmth, but her laissez-faire approach does little to boost the play’s credibility. Mary Ann Thebus makes a compelling and at times heartbreaking Mommo, but letting her chatter on in unwavering cadences all evening turns her into a sonic nuisance. Michelle Courvais and Elizabeth Rich are believable as Dolly and Mary, but neither displays the kind of attachment to Mommo that would prevent them from putting her in the oft invoked county home, a shortcoming that vitiates the play’s reason for being.