A peaceful, small town is ripped asunder as its children go missing and many are found wandering disoriented or dead. Someone - or something - is hunting them down one by one. Coming to a place where trust in anyone is non-existent and faith in a solution is fading fast, Beckett and Duran must team up with one victim's brother to track down the monster hunting the children and discover who's pulling his strings in part one of 'Welcome to Arlington.'