Jon Briddell

When an 8-year-old is found murdered on the Appalachian Trail, the BAU team goes deep into its forests in search of a man lurking in the wilderness who is targeting children.

Torres’ half-sister, Ava, who is incarcerated in a juvenile corrections facility, mysteriously re-enters Torres’ life when a fellow inmate vanishes. Meanwhile, the Lightman Group becomes embroiled in a case that forces the sisters to revisit their troubled upbringing.

Much to Bell’s dismay, Nic and Conrad decide to admit a homeless Jane Doe, whom they suspect was dumped off by another hospital during Chastain’s big Charity Ball. Elsewhere in the hospital, Devon and Irving care for a male escort who offers surprisingly good advice, Micah returns for a checkup and falls even harder for Mina, and Devon’s parents are in town.

CSI is called to investigate a banquet celebrating the sale of a university-developed medical technology to a defense contractor, after a number of guests suddenly grow ill, with three people dying.

Ben's discovery in the attic further exacerbates his tension with Christy, who, to make matters worse, continues to keep the kids away from him. When Ben finally does get some much needed father-daughter time with Abby at the Christmas fair, an unwelcome guest changes the course of the evening. Meanwhile, after the leak in the crime lab left most of the forensic evidence in Tom's case unusable, Det. Cornell refuses to sit idly by and wait for everything to be re-tested. She returns to the crime scene, hoping to find something new to drive her towards an arrest.