Farina and Parisse, who played Joe Fontana and Alexandra Borgia, respectively, left the series at the end of the 16th season.

Imperioli, who had played Nick Falco during Martin's brief absence from the show in season 15, made a guest appearance (his last in the franchise) in the episode "Hindsight."

When the body of Patrick Sullivan is found with Olivia Benson's number in his cell phone, Green and Fontana call the Special Victims Unit squad to help them with their case.

Although not initially clear, the detectives soon realize that Sullivan is connected to Lorraine Dillon (Lynda Carter) and April Troost (Estella Warren), career criminals that Benson had previously been unable to catch.

In a legal gambit, Executive ADA Jack McCoy must then risk his career, and those of others, as well; bending the rules and using corrupt DEA Agent Almonte (Ritchie Coster) to lure out the sadistic psychopaths.