Detectives Benson and Stabler arrive on the scene where a woman is found dead in Bethesda Fountain. When her squeaky clean image doesn't match up with her promiscuous actions on the night of her murder, ADA Mikka Von encourages the cops to dig deeper into her past. When they find out that the woman was poisoned with toxic mushrooms, they suspect a crazed activist and professor is responsible. As the case develops, Benson and Stabler go to dangerous lengths to ensure that justice is served.

After a young woman has been raped and murdered, her body turns up in an industrial laundry facility. Detectives Benson and Stabler soon find that she was involved in an environmental group called CLEAN, and it isn't long before they track down the prime suspect. However, the case soon puts them in the line of fire and exposes a much larger mystery that includes even more victims. As the investigation progresses, Detective Benson builds a connection to a victim's daughter that invokes her own past in ways she never anticipated.