Guest Stars Debbie Allen as Dr. Catherine Avery Amanda Fuller as Morgan Peterson Summer Glau as Nurse Emily Kovach James Avery as Sam Rebecca Hazlewood as Dr. Mara Keaton Co Starring Payton Silver as Dr. A. Knox Teresa Huang as Nurse Ruth Chelsea Harris as Lori Bosson Ginny McMath as Irene Charles Emmett as Mr. Bosson Rosalyn Sidewater as Mrs. Bosson