The expert cast, under Joe Mantello's thoughtful direction, mines the resulting conflicts for all their hilarity and poignance. After Brooke pours her heart out defending her book, Thomas Sadoski's witty Trip offers an equally passionate (and entertaining) summation of the selfishness in her suffering and healing. And when Channing's pitch-perfect Polly clashes with her sister - a recovering alcoholic, played by Judith Light, who suggests what Brooke might become if she fully disappeared up her own navel - neither is victorious or vanquished.