This is a true tear-jerker, so even if you think you're immune, keep those hankies close at hand. In the labyrinthian ways of Hollywood, Stepmom, the book by Maggie Robb, is based on a story by Gigi Levangie and a screenplay by Ms. Levangie and many others. Here, Stepmom, the audio version (3 hours), is read by Blair Brown, who skillfully performs all three parts: Jackie, the super-mom, totally devoted to her son and daughter; Luke, her former husband, driven away by Jackie's all-consuming involvement with the children; and Isabelle, young, glamorous, madly in love with Luke. The kids are there, too, bewildered by the divorce, unsettled by this young woman who has taken a place in their father's heart. What finally brings them all together, what makes them all reach into the recesses of their hearts, will reach into yours and tug hard at its strings.