M3, T20: In the conclusion of a two-part crossover story line begun in "ER" episode Number #227269, "Brothers & Sisters," Dr. Susan Lewis ("ER" series star Sherry Stringfield) has traveled from Chicago to New York to search for her missing 6-year-old niece, Suzy (Gianna Beleno), the daughter of Lewis' trouble-prone sister, Chloe ("ER" recurring guest star Kathleen Wilhoite). After interviewing witnesses who maintain that a man in uniform took the child, Yokas and Bosco focus their attention on Suzy's stepfather, a New Jersey cop. Meanwhile, Sully's capricious wife, Tatiana (recurring guest star Savannah Haske), returns. And Doherty enjoys even mundane household chores if he gets to spend time with his young son, Joey (recurring guest star Kristopher Scott Fiedel).