DR. WEAVER MAY LOSE BABY WHILE DR. CARTER MAKES WAVES IN FAMILY FORTUNE; THANDIE NEWTON RETURNS TO GUEST-STAR -- A panic-stricken Dr. Weaver (Laura Innes) faces a life-defining moment when she is ordered to give up her son to the Lopez family while Dr. Carter (Noah Wyle) greets a returning Kem (guest star Thandie Newton, "Mission: Impossible 2") -- but their meeting with his father (guest star Michael Gross, "Family Ties") is tense after Carter anounces plans for his grandmother's estate. Elsewhere, Abby (Maura Tierney) is in the midst of her psychiatric rotation and tries to help a seizure-prone mother (as Jordan, guest star Julianne Nicholson) with a controversial drug treatment. Meanwhile, Neela (Parminder Nagra) impresses everyone with her lab research, especially when she helps one of the reckless students (as Yuri, guest star Archie Kao) after he experiments on himself. In addition, Dr. Kovac's (Goran Visnjic) relationship with Sam (Linda Cardellini) and her son Alex (guest star Oliver Davis) grows awkward when Alex' father returns. Alex Kingston, Ming-Na and Mekhi Phifer also star. TV-14