The team investigates when a young paramedic with gang ties disappears. Jack and Ann bond over their recent losses.

When a school teacher goes missing, the team's investigation leads them to suspect that she may have been too closely connected to a student.

When Leah Robinson goes missing after a confrontation with a young man at an art gallery, the team mvoes in to investigate and soon become suspicious of Leah, suspecting her of murdering young women that she believed to be involved with her husband, Ken. Ann isn't quite ready to take her romance with Jack public, and their relationship gets rocky when their different methods of handling the case tip off the suspect.

The team investigates after five-year-old Ethan Heller is carjacked from the family car, and Danny starts to figure out what's going on with Martin.

When a young, interracial boy goes missing, race and money appear to play the starring roles in the investigation.

Malone and his team start off the new year investigating how a private investigator might have went missing.

The team uncovers a history of deception as they search for a man posing as a college student vanishes.

After Hanna's boyfriend disappears from Chicago along the way to New York, Jack hesitates to assign the team on his case.