At the exact center of Joan Vail Thorne’s play, Broadway and TV vet Frances Sternhagen (Cheers) masterfully portrays the blue-blooded matriarch who serves her family and friends both tea and daggers. Guarding her pain with a veneer of Southern charm, she would rather tell trivial tales than face the problem under her turned-up nose — that her son’s recent marriage has rendered her obsolete. Despite amusing anecdotes and insightful biblical allusions, the hollow script of The Exact Center of the Universe leaves Sternhagen uttering too many exclamations with too few points. B-