DESPERATE ABBY LOOKS FOR DISTURBED AND AWOL BROTHER; OSCAR WINNER SALLY FIELD RETURNS TO GUEST STAR -- Abby's (Maura Tierney) family nightmare continues when she goes in search of her AWOL brother (guest star Thomas Everett Scott)

whom she suspects is suffering from the same bi-polar mental problems as her mother (Oscar-winning guest star Sally Field, "Norma Rae") and the two women meet at a Midwestern air force base in hopes of preventing his military court-martial. Back at the snowed-in hospital, Dr. Carter (Noah Wyle) struggles to get out of Chicago to join Abby while Dr. Corday (Alex Kingston) treats a family of patients who are severely injured by a truck driver while building a snowman. Meanwhile, Corday tries to help the father make a life-or-death decision while she sympathizes with the troubled Dr. Nathan (guest star Don Cheadle) as he struggles with his increasing symptoms of Parkinson's disease. Laura Innes, Goran Visnjic, Sherry Stringfield and Sharif Atkins also star.