DIANNE WIEST JOINS CAST IN SEASON PREMIERE; NEW YORK MAYOR RUDOLPH GUILIANI GUEST-STARS - A suspicious apartment fire leaves a severely disabled boy dead of smoke inhalation. Though an antique store owner in the same building had been "victim" to several other fires in the past, Detectives Briscoe (Jerry Orbach) and Green (Jesse L. Martin) are drawn to suspects closer to home as they discover the tremendous burden the young boy posed to his parents and their failed marriage during his twelve years. As more is learned about the devoted mother (guest star Megan Follows), even A.D.A. Jack McCoy (Sam Waterston) begins to question whether his prosecutorial direction is truly in the service of justice. In a guest appearance as himself, New York Mayor Rudolph Giuliani introduces District Attorney Nora Lewin (Dianne Wiest) to McCoy and Carmichael (Angie Harmon).