On Monday morning, Agent Locke arrives exhausted after working the active murder case with Agent Briggs. She tells Cassie, Dean, and the others that the investigation has stalled, there are now three bodies, and the killer is escalating. Locke shifts the lesson to victimology, explaining that understanding a victim's habits, personality, and likely reactions can reveal what the killer wanted and how the crime unfolded.

Dean explains that killers often choose victims by type, convenience, or symbolic substitution, and that a victim's response can shape the crime scene. This makes Cassie think of her mother's bloody dressing room. Cassie realizes that her mother would have fought unless she believed Cassie was about to return and chose to go with the attacker to protect her.

Locke gives Cassie a hypothetical case involving a highly controlled victim who, unlike earlier victims, had no defensive wounds and was killed quickly. Cassie reasons that the victim did not physically fight but probably tried to reason with or manipulate the killer, disrupting his need for control. Cassie concludes that the UNSUB killed the earlier victims for pleasure but killed this victim in rage, while Dean notices that the killer must have rebuttoned the victim's shirt afterward.

Locke uses the example to show that investigators must question assumptions about both victims and killers. Sloane enters with statistics about serial killers, and Briggs arrives with news from Starmans: a fourth body has been found, a palm reader in Dupont Circle. Briggs also reveals that a database search found three previous cases with the same MO in New Orleans, Los Angeles, and American Falls, Idaho, suggesting the killer may have crossed state lines and been active for months.

Briggs initially wants to discuss the case away from the teenagers, but Cassie challenges him by pointing out that he once sought Dean's help when Dean was twelve. Judd tries to defuse the tension by offering to put the kids to work outside, but Locke lets them stay. Briggs and Locke prepare to leave at sixteen hundred hours, and Locke refuses to give Cassie a cold case yet, assigning her prison interview binders instead. Dean unexpectedly argues that Cassie can handle more, but when Locke tells Cassie to study the prison interviews, Dean warns flatly that it is not a good idea.