GUNPLAY IN EMERGENCY ROOM PROMPTS DEFIANT CARTER TO LEAD INSURRECTION

After an enraged drug addict pulls a gun on Dr. Chen (Ming-Na) and other staff members, a fed-up Dr. Carter (Noah Wyle) leads a divisive walkout when his request for metal detectors is delayed -- thereby endangering the lives of new patients. Elsewhere, Dr. Lewis (Sherry Stringfield) counsels an exhausted elderly woman (guest star Shirley Knight) whose adult son is dying from Huntington's disease -- the same affliction that killed her husband. In addition, Dr. Pratt (Mekhi Phifer) tries to safeguard his developmentally disabled brother (guest star Marcello Thedford) and comforts Chen after her brush with death; Dr. Kovac (Goran Visnjic) treats an HIV-infected boy whose parents arouse his curiosity; and Abby's (Maura Tierney) brother (guest star Thomas Everett Scott) gets an eyeful when he visits the hospital. Laura Innes, Paul McCrane and Sharif Atkins also star.