When the SWAT team is called in to work on their day off to end a hostage situation, they discover one of the captives is a wanted felon. Also, when Hondo saves his sister, Brianna, after she's been roofied at a nightclub, he uses his day off to hunt a serial rapist.

The SWAT team faces difficult reminders of a past school shooting when they receive a warning that a copycat plans to re-enact the crime. As the team races to stop the new threat, they flash back to the day of the tense first mission.