S18, E1: A young boy is found wandering alone in Central Park and the search for his parents leads to startling evidence of a planned mass casualty event in the city. As the SVU works with the joint terrorism task force to find the suspects and the motive, Lt. Benson (Mariska Hargitay) must also convince Barba (Raúl Esparza) to address allegations of rape and torture the boy's mother discloses.