Finally there comes a turning point, about an hour and 15 minutes into the show, when Mr. Rickman is allowed to embody something more than brisk intellectual sadism. Handed a really good piece of writing by one of his students, Leonard responds with a quietly potent mix of antagonism, humility, fear and something like joy. Of course this mélange of feelings, magnificently orchestrated by Mr. Rickman, is arrived at after Leonard has only glanced at the first couple of pages of a vast manuscript. But for the first time I felt an authentic rush of pleasure and the exhilaration of being reminded that in theater, art comes less from landing lines than in finding what lies between them.