A.J. Achinger

When teenagers who were reported missing are suspected of a series of mass murders in Chicago, the BAU investigates their whereabouts to find a motive for the crimes.

As Derek prepares for his move to DC, Meredith keeps herself busy at the hospital. Meanwhile, Jackson and April deal with difficult news, and Arizona and Amelia discuss how to best approach Dr. Herman.

Frankie Jr. is brought in to help with a gruesome murder case involving a youth hockey league. Frustrated with Hope (recurring guest star SHARON LAWRENCE), Cailin (recurring guest star EMILEE WALLACE) asks to stay with Maura. But Maura quickly learns that living with her younger half-sister requires skills she does not have.

Emmalin's college issues and Michael's unclear career path put a strain on their relationship and Claudia Joy is forced to choose sides. Denise returns to work. Roxy supports Trevor as he decides whether to apply to Officer Candidate School.