A severe heat wave wreaks havoc on the city, making life on the streets even more perilous for the new members of the squad. The danger multiplies with the discovery that a serial rapist may be on the loose. Amid the chaos, Andy is cut off from her backup during a sudden citywide blackout and is challenged with taking down a vicious predator -- alone. Meanwhile, Andy also makes an unexpected romantic decision that's certain to complicate her life on and off the job.

Chris and Gail's investigation into a messy highway accident leads to the discovery of a license plate matching an Amber Alert for a missing nine-year-old girl. Division 15 embarks on a massive manhunt to find the girl and the car's missing driver. Meanwhile, an intense interrogation of the parents uncovers disturbing evidence. More secrets unravel, as the entire division races the clock to find the young victim - hoping it's not too late