Hoping to encourage more students to join the Adopt-A-Grandparent program, Sabrina finds a mischievous way to get trend-setting Libby to participate: she impersonates her, necessitating quick Superman-style telephone booth transformation whenever the (increasingly puzzled) real Libby turns up. But Sabrina's well-meant scheme goes wrong when Libby bonds with Sabrina's adopted grandmother Nana, who claims to know most of Hollywood's young hunks personally. Meanwhile, Zelda can't decide whether to continue dating a man who is centuries younger than she is; and Hilda and Salem eat too much of a magical "hair soup" that causes their hair to grow at an exponential rate.