Tread Perilously opens the case files of the Special Review Unit for the Law Order: SVU episode "Born Psychopath."

When the detectives of the Special Victims Unit are called out to a case of possible child abuse, Detective Nick Amaro encounters a boy beyond the help of his affluent parents. Soon, it becomes clear that if the boy isn't a genuine psychopath, he is a letter-perfect example of the profile. Bane is his favorite superhero. While the parents are reluctant to accept the truth, the SVU team gets ready for an unfortunate outcome. Also, Amaro resolves to tell his recently-discovered son the truth about their relationship.

Executive Assistant District Attorney Louis Allred joins the Review Unit as Erik freaks Justin out by showing him a crazy kid episode shortly before the birth of his child. The trio obsess over a Russian nanny that the episode quickly forgets about. Justin and Erik begin pitching a horror movie called "Peek-a-Boo." Justin quickly recognizes Amaro as Armadillo from The Shield. The group also imagines the DuckTales version of Tiny Fey. Louis and Erik attempt to recreate train-song. Louis questions the wisdom of telling your children the combination to the gun safe and Justin learns that protection rackets are cyclical.