Walker's friend Dr.Carlisle,a pediatric surgeon,is killed.Walker learns that Carlisle had taken out a restraining order on the father of a young girl who had died in his care.The suspect vanishes and Walker chases,leading to a tense confrontation.Walker's friend Dr.Carlisle,a pediatric surgeon,is killed.Walker learns that Carlisle had taken out a restraining order on the father of a young girl who had died in his care.The suspect vanishes and Walker chases,leading to a tense confrontation.